Azithromycin derivatives containing a phosphonium ion as anticancer agents

ABSTRACT

This invention relates to compounds that are useful as cancer therapies. The compounds comprise azithromycin derivatives having a phosphonium cation tethered to the azithromycin macrocycle. The invention also relates to methods of using said compounds and the pharmaceutical formulations comprising said compounds.

RELATED APPLICATIONS

This application is a U.S. National Stage of International Application No. PCT/EP2018/060245, filed Apr. 20, 2018; which claims priority to Great Britain Application No. 1721752.2, filed Dec. 22, 2017; and Great Britain Application No. 1706309.0; filed Apr. 20, 2017.

This invention relates to compounds that disrupt cell function, such as the disruption of cell metabolism in particular cancer cell metabolism, that are useful as cancer therapies. The compounds comprise azithromycin derivatives having a phosphonium cation tethered to the azithromycin macrocycle. The invention also relates to methods of using said compounds and to pharmaceutical formulations comprising said compounds.

BACKGROUND

Cancer is the fourth greatest cause of mortality in the developed world. In 2016 it was predicted that more than 1.6 million new cases of cancer would be diagnosed in the U.S. alone, and that cancer would be responsible for nearly 600,000 U.S. deaths.

Cancer is characterized by the unregulated proliferation of cells, which disrupt the function of tissues. The proliferation of cells can be caused by an abnormal increase in cell production or a disruption in the cell death pathway. In any event, disruptors of cell function can impact the proliferation of cells and in particular cancer cells by reducing or inhibiting cell proliferation. For example, the modulation of cancer cell metabolism can lead to the reduction or inhibition of cell proliferation. Equally, the compounds of the invention may reduce, disrupt, or inhibit the growth or proliferation of a cancer cell or it may induce the death of a cancer cell. As such, cancer cell metabolism, and reducing cell proliferation, is a potential target for disrupting cancer growth and ultimately a therapeutic pathway for cancer treatment. Accordingly, the certain embodiments of the invention contemplate compounds that modulate cancer cell metabolism and/or reduce cell proliferation. Reduction in cell proliferation could be achieved either by increasing cell death or by reducing the rate of cell growth.

It has been observed that certain compounds having antibiotic activity have a beneficial effect when administered to patients with cancer. The inventors have found that compounds having a phosphonium ion linked to azithromycin are able to modulate cancer cell metabolism in cancer cell lines and, accordingly, prevent and/or treat cancer.

The “prevention” of cancer may be taken as including the prevention of the formation of tumours, including primary tumours, metastatic tumours, or tumours associated with cancer onset, resistance or relapse. The prevention of cancer may also be taken as encompassing the prevention of the progression of cancer. In this context, prevention of development of cancer may be demonstrated by preventing an increase in the “stage” of a tumour (using an appropriate cancer staging method) that has been treated using the compounds of the invention. The prevention of increase in cancer stage may be compared to progression of an untreated tumour, or compared to the extent of progression that would be expected by a clinician in the event that the tumour was not treated.

The “treatment” of cancer may be taken as including any improvement of pathology, symptoms or prognosis that is achieved in respect of cancer in a subject receiving compounds of the invention. Treatment may be indicated by a partial improvement of such indications, or by a total improvement (e.g. the absence of cancer following medical use of the compounds of the invention).

Accordingly, the prevention and/or treatment as defined above are intended aims of certain embodiments of the invention. The above definitions of treatment or prevention of cancer apply equally to the specific forms of cancer that are also contemplated.

Recent developments in cancer therapy have suggested that certain antibiotic compounds may be useful in cancer treatment. The mechanisms by which these agents, which include the antibiotics azithromycin and doxycycline, exert a therapeutic effect have been open to markedly different explanations. Some authors have suggested that these agents inhibit matrix metalloproteinases (MMPs) and thereby achieve an anti-inflammatory effect, while others suggest that they impair the cells' response to DNA damage, thereby increasing the effectiveness of chemotherapy or radiotherapy on bulk tumour cells. Still other articles have indicated that the antibiotics target mitochondrial function.

However, there have also been reports that antibiotic use can increase risk of colorectal cancer. A recent study identified that increasing duration of antibiotic use was significantly associated with an increased risk of colorectal adenoma (Cao Y, Wu K, Mehta R, et al, “Long-term use of antibiotics and risk of colorectal adenoma”, Gut, 2017, 0, page 1-7).

Surprisingly, the inventors have found that the compounds having a phosphonium ion linked to azithromycin have increased activity against certain cancer cell lines compared to azithromycin itself. This is demonstrated by the reduced cancer cell proliferation observed in a cell confluence assay.

Also provided is a method of preventing and/or treating cancer in a subject needing such prevention and/or treatment, the method comprising administering a therapeutically effective amount of a compound of the invention to the subject. A therapeutically effective amount of a compound of the invention may be an amount of such a compound sufficient to treat a variety of cancers, including the modulation of cancer cells or other dysfunctional cells (such as tumour initiating cells, stem-like cancer cells, cancer stem cells, or a population of cells with stem cell-like features that exist in tumors and that give rise to the bulk of tumor cells with more differentiated phenotypes). References to cancer cells include hybrid and giant cells. It will be appreciated that the therapeutically effective amount of the compound of the invention may be provided in a single incidence of administration, or cumulatively through multiple incidences of administration.

The same considerations regarding the types of cancers to be treated, and benefits provided by treatment, described with respect to the medical uses of the compounds of the invention also apply to the methods of treatment of the invention.

BRIEF SUMMARY OF THE DISCLOSURE

In a first aspect of the invention there is provided a compound comprising an ion of formula (I) or a pharmaceutically acceptable salt thereof:

wherein either Z¹ is

and Z² is R^(4b); or Z² is

and Z¹ is R^(2b); Z³ is independently selected from H, C(O)—C₁-C₆-alkyl or Z³ has the structure:

Z⁴ is independently selected from H, C(O)—C₁-C₆-alkyl or Z⁴ has the structure:

-L¹- is independently absent or is selected from —C(O)—, —C(O)O—, —S(O)₂—, —S(O)—, —C(O)NR⁵, and —S(O)₂NR⁵—; -L³- is independently at each occurrence either absent or selected from: —O—, —S—, —NR⁶—, —C(O)—, —OC(O)—, —C(O)O—, —S(O)₂—, —S(O)—, —NR⁵C(O)—, —C(O)NR⁵, —NR⁵S(O)₂—, —S(O)₂NR⁵—, —OC(O)NR⁵—, —NR⁵C(O)O—, NR⁵C(O)NR⁵, —CR⁷═CR⁷— and —C≡C—; -L²- and -L⁴- are each independently at each occurrence —C₁-C₄-alkylene-, each alkylene group being unsubstituted or substituted with from 1 to 6 independently selected R⁸ groups; provided that any -L₂- or -L₄- group that is attached at each end to an atom selected from oxygen, nitrogen, sulphur or phosphorous is —C₂-C₄-alkylene-; -L⁵- is independently absent or is selected from: —C(O)— and —C(O)NR⁵—; n is an integer selected from 0, 1, 2, 3, 4 and 5; wherein L¹, L², L³, L⁴, L⁵ and n are selected such that length of the linker formed by those groups is from 3 to 16 atoms; R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl; wherein said phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl is optionally substituted with from 1 to 5 independently selected R^(1d) groups; and wherein said C₃ to C₈-cycloalkyl, C₁-C₅-alkyl and 4- to 8-membered heterocycloalkyl is optionally substituted with from 1 to 5 independently selected R^(1e) groups; provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl; wherein R^(1a) and R^(1b) are optionally connected to each other via a bond or a group selected from —O—, NR^(6a), and C₁-C₃-alkylene; R^(1d) is independently at each occurrence selected from: C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, 5- to 8-membered heterocycloalkyl, 5-, 6-, 9- or 10-membered heteroaryl, phenyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R^(1e) is independently at each occurrence selected from: oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, 5- to 8-membered heterocycloalkyl, 5-, 6-, 9- or 10-membered heteroaryl, phenyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R^(2a), R^(2b) and R^(2c) are each independently selected from H and C₁-C₆-alkyl; R^(3a) is independently selected from: H, C₁-C₆-alkyl and C(O)—C₁-C₆-alkyl; R^(3b) and R^(3c) are each independently selected from: H and C(O)—C₁-C₆-alkyl; R^(4a) and R^(4b) are each independently selected from: H, C₁-C₆-alkyl and C(O)—C₁-C₆-alkyl; or R^(4a) and R^(4b) taken together form C(O); R^(5a) and R^(6a) are each independently at each occurrence selected from H and C₁-C₆-alkyl; R⁶ and R¹¹ are each independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl; R⁷ is independently at each occurrence selected from H, C₁-C₄-alkyl and halo; R⁸ is independently at each occurrence selected from: C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R⁹ is independently at each occurrence selected from: H, C₁-C₆-alkyl and C₁-C₆-haloalkyl; R¹⁰ is independently at each occurrence selected from: H and C₁-C₆-alkyl; and wherein any of the abovementioned alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, heteroaryl or phenyl groups is optionally substituted where chemically allowable by from 1 to 4 groups independently selected from oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, OR^(a), NR^(a)R^(b), SR^(a), C(O)OR^(a), C(O)NR^(a)R^(a), halo, cyano, nitro, C(O)R^(a), S(O)₂OR^(a), S(O)₂R^(a), S(O)R^(a) and S(O)₂NR^(a)R^(a); wherein R^(a) is independently at each occurrence selected from: H and C₁-C₆-alkyl; and R^(b) is independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl.

A compound comprising anion of formula (I) or a pharmaceutically acceptable salt thereof:

wherein either Z¹ is

and Z² is R^(4b); or Z² is

and Z¹ is R^(2b); Z³ is independently selected from H, C(O)—C₁-C₆-alkyl or Z³ has the structure:

Z⁴ is independently selected from H, C(O)—C₁-C₆-alkyl or Z⁴ has the structure:

-L¹- is independently absent or is selected from —C(O)—, —C(O)O—, —S(O)₂—, —S(O)—, —C(O)NR⁵, and —S(O)₂NR⁵—; -L³- is independently at each occurrence either absent or selected from: —O—, —S—, —NR⁶—, —C(O)—, —OC(O)—, —C(O)O—, —S(O)₂—, —S(O)—, —NR⁵C(O)—, —C(O)NR⁵, —NR⁵S(O)₂—, —S(O)₂NR⁵—, —OC(O)NR⁵—, —NR⁵C(O)O—, NR⁵C(O)NR⁵, —CR⁷═CR⁷— and —C≡C—; -L²- and -L⁴- are each independently at each occurrence —C₁-C₄-alkylene-, each alkylene group being unsubstituted or substituted with from 1 to 6 independently selected R⁸ groups; provided that any -L₂- or -L₄- group that is attached at each end to an atom selected from oxygen, nitrogen, sulphur or phosphorous is —C₂-C₄-alkylene-; -L⁵- is independently absent or is selected from: —C(O)— and —C(O)NR⁵—; n is an integer selected from 0, 1, 2, 3, 4 and 5; wherein L, L², L³, L⁴, L⁵ and n are selected such that length of the linker formed by those groups is from 3 to 16 atoms; R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl; wherein said phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl is optionally substituted with from 1 to 5 independently selected R^(1d) groups; and wherein said C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl is optionally substituted with from 1 to 5 independently selected R^(1e) groups; provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl; R^(1d) is independently at each occurrence selected from: C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, 5- to 8-membered heterocycloalkyl, 5-, 6-, 9- or 10-membered heteroaryl, phenyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R^(1e) is independently at each occurrence selected from: oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, 5- to 8-membered heterocycloalkyl, 5-, 6-, 9- or 10-membered heteroaryl, phenyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R^(2a), R^(2b) and R^(2c) are each independently selected from H and C₁-C₆-alkyl; R^(3a) is independently selected from: H, C₁-C₆-alkyl and C(O)—C₁-C₆-alkyl; R^(3b) and R^(3c) are each independently selected from: H and C(O)—C₁-C₆-alkyl; R^(4a) and R^(4b) are each independently selected from: H, C₁-C₆-alkyl and C(O)—C₁-C₆-alkyl; or R^(4a) and R^(4b) taken together form C(O); R⁵ is independently at each occurrence selected from H and C₁-C₆-alkyl; R⁶ and R¹¹ are each independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl; R⁷ is independently at each occurrence selected from H, C₁-C₄-alkyl and halo; R⁸ is independently at each occurrence selected from: C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)₂R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R⁹ is independently at each occurrence selected from: H, C₁-C₆-alkyl and C₁-C₆-haloalkyl; R¹⁰ is independently at each occurrence selected from: H and C₁-C₆-alkyl; and wherein any of the abovementioned alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, heteroaryl or phenyl groups is optionally substituted where chemically allowable by from 1 to 4 groups independently selected from oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, OR^(a), NR^(a)R^(b), SR^(a), C(O)OR^(a), C(O)NR^(a)R^(a), halo, cyano, nitro, C(O)R^(a), S(O)₂OR^(a), S(O)₂R^(a), S(O)R^(a) and S(O)₂NR^(a)R^(a); wherein R^(a) is independently at each occurrence selected from: H and C₁-C₆-alkyl; and R^(b) is independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl.

For the absence of doubt, where n is greater than 1, each -L³-L⁴- unit is selected independently of the other each -L³-L⁴- unit or -L³-L⁴- units. Thus, each -L³-L⁴- unit may be the same or they may be different.

For the absence of doubt the atom length of the linkers formed by L¹, L², L³ L⁴ and L⁵ is the number of atoms in a straight chain from the phosphorous atom of the phosphonium to the oxygen or nitrogen atom via which the linker is attached to the azithromycin portion of the molecules. The length does not include any substituents or branching that might be present on the chain.

For the absence of doubt where a bivalent group (e.g. L¹, L², L³, L⁴, L⁵ or a combination thereof) is represented in text, the left hand portion of the linker group is attached, either directly or indirectly, to the carbon or nitrogen atom via which the linker is attached to the azithromycin portion of the ions and the right hand portion of the linker group is attached, either directly or indirectly, to the phosphorous atom of the phosphonium.

In embodiments, the ion of formula (I) is an ion of formula (II):

In embodiments the ion of formula (I) is an ion of formula (IIIa) and (IIIb):

In embodiments, the ion of formula (I) is an ion of formula (IVa) and (IVb):

In embodiments the ion of formula (I) is an ion of formula (Va) and (Vb):

wherein L⁶ is a C₂-C₁₅-alkylene group optionally substituted with from 0 to 10 R⁸ groups.

In embodiments, the ion of formula (I) is an ion of formula (VIa) and (VIb):

wherein L⁷ is a C₃-C₁₆-alkylene group optionally substituted with from 0 to 10 R⁸ groups.

In embodiments the ion of formula (I) is an ion of formula (VIIa) and (VIIb):

wherein L⁸ is a C₂-C₁₃-alkylene group optionally substituted with from 0 to 10 R³ groups.

The following statements apply to compounds of any of formulae (I) to (VIIb). These statements are independent and interchangeable. In other words, any of the features described in any one of the following statements may (where chemically allowable) be combined with the features described in one or more other statements below. In particular, where a compound is exemplified or illustrated in this specification, any two or more of the statements below which describe a feature of that compound, expressed at any level of generality, may be combined so as to represent subject matter which is contemplated as forming part of the disclosure of this invention in this specification.

In embodiments, Z¹ is

and Z² is R^(4b).

In embodiments, Z² is

and Z¹ is R^(2b).

In embodiments, Z³ is

In embodiments, Z³ is

or H.

In embodiments, Z³ is

In embodiments, Z³ is H.

In embodiments, Z³ is

wherein R^(3c) is H.

In embodiments, Z³ is

wherein R^(3c) is H.

In embodiments, Z⁴ is

or H.

In embodiments, Z⁴ is

In embodiments, Z⁴ is H.

In embodiments, R^(2a) is C₁-C₆-alkyl. In embodiments, R^(2a) is methyl. In embodiments, R^(2c) is C₁-C₆-alkyl. In embodiments, R^(2c) is methyl. In embodiments, R^(2a) is C₁-C₆-alkyl and R^(2c) is C₁-C₆-alkyl. In embodiments, R^(2a) is methyl and R^(2c) is methyl. In embodiments, R^(2b) (when present) is methyl. In embodiments, R^(2a) is methyl, R^(2b) (when present) is methyl and R^(2c) is methyl.

In embodiments, R^(3a) is H. In embodiments, R^(3b) is H or C(O)CH₃. In embodiments, R^(3b) is H. In embodiments, R^(3b) is C(O)CH₃. In embodiments, R^(3c) is H. In embodiments, R^(3a) is H and R^(3b) is H. In embodiments, R^(3a) is H and R^(3b) is C(O)CH₃. In embodiments, R^(3a) is H, R^(3b) is C(O)CH₃ and R^(3c) is H. In embodiments, R^(3a) is H, R^(3b) is H and R^(3c) is H.

In embodiments, R^(4a) is H. In embodiments, R^(4b) is H. In embodiments, R^(4a) is H and R^(4b) is H. In embodiments, R^(4a) and R^(4b) together form C(O).

In embodiments, Z³ is

R³ is H, R^(2a) is C₁-C₈-alkyl; R^(2b) is C₁-C₆-alkyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z³ is

R^(3c) is H, R^(2a) is methyl; R^(2c) is methyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z³ is

R^(3c) is H, R^(2a) is C₁-C₆-alkyl; R^(2c) is C₁-C₆-alkyl; R^(3a) is H; R^(3b) is H; R^(4a) is H and R^(4b) (when present) is H.

In embodiments, Z^(3c) is

R^(3c) is H, R^(2a) is methyl; R^(2c) is methyl; R^(3a) is H; R^(3b) is H, R^(4a) is H and R^(4b) (when present) is H.

In embodiments, Z⁴ is

R^(2a) is C₁-C₆-alkyl; R^(2b) is C₁-C₆-alkyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z⁴ is

R^(2a) is methyl; R^(2c) is methyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z⁴ is

R² is C₁-C₆-alkyl; R^(2c) is C₁-C₆-alkyl; R^(3a) is H; R^(3b) is H; R^(4a) is H and R^(4b) (when present) is H.

In embodiments, Z⁴ is

R^(2a) is methyl; R^(2c) is methyl; R^(3a) is H; R^(3b) is H, R^(4a) is H and R^(4b) (when present) is H.

In embodiments, Z³ is H and Z⁴ is H.

In embodiments, Z³ is

and Z⁴ is

optionally wherein R^(3c) is H, R^(2a) is C₁-C₆-alkyl; R² is C₁-C₆-alkyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z³ is H, R^(2a) is C₁-C₆-alkyl; R^(2b) is C₁-C₆-alkyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z³ is H, R^(2a) is methyl; R^(2c) is methyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z³ is H, R^(2a) is C₁-C₆-alkyl; R^(2c) is C₁-C₆-alkyl; R^(3a) is H; R^(3b) is H; R^(4a) is H and R^(4b) (when present) is H.

In embodiments, Z³ is H, R^(2a) is methyl; R^(2c) is methyl; R^(3a) is H; R^(3b) is H, R^(4a) is H and R^(4b) (when present) is H.

In embodiments, Z⁴ is H, R^(2a) is C₁-C₆-alkyl; R^(2b) is C₁-C₆-alkyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z⁴ is H, R^(2a) is methyl; R^(2c) is methyl; R^(3a) is H and R^(3b) is H.

In embodiments, Z⁴ is H, R^(2a) is C₁-C₆-alkyl; R^(2c) is C₁-C₆-alkyl; R^(3a) is H; R^(3b) is H; R^(4a) is H and R^(4b) (when present) is H.

In embodiments, Z⁴ is H, R^(2a) is methyl; R^(2c) is methyl; R^(3a) is H; R^(3b) is H, R^(4a) is H and R^(4b) (when present) is H.

In embodiments, R⁵ is at any particular occurrence H. In embodiments, R⁵ is at each occurrence H.

In embodiments, R⁵ is at any particular occurrence C₁-C₄-alkyl, e.g. methyl. In embodiments, R⁵ is at each occurrence C₁-C₄-alkyl, e.g. methyl.

In embodiments, R⁶ is at any particular occurrence H. In embodiments, R⁶ is at each occurrence H.

In embodiments, R⁶ is at any particular occurrence C₁-C₄-alkyl, e.g. methyl. In embodiments, R⁶ is at each occurrence C₁-C₄-alkyl, e.g. methyl.

In embodiments, R⁷ is at any particular occurrence H. In embodiments, R⁷ is at each occurrence H.

In embodiments, R⁸ is at any particular occurrence C₁-C₄-alkyl, e.g. methyl. In embodiments, R⁸ is at each occurrence C₁-C₄-alkyl, e.g. methyl.

In embodiments, R⁹ is at any particular occurrence H. In embodiments, R⁹ is at each occurrence H.

In embodiments, R⁹ is at any particular occurrence C₁-C₄-alkyl, e.g. methyl. In embodiments, R⁹ is at each occurrence C₁-C₄-alkyl, e.g. methyl.

In embodiments, R¹⁰ is at any particular occurrence H. In embodiments, R¹⁰ is at each occurrence H.

In embodiments, R¹⁰ is at any particular occurrence C₁-C₄-alkyl, e.g. methyl. In embodiments, R¹⁰ is at each occurrence C₁-C₄-alkyl, e.g. methyl.

In embodiments, R¹¹ is at any particular occurrence H. In embodiments, R¹¹ is at each occurrence H.

In embodiments, R¹¹ is at any particular occurrence C₁-C₄-alkyl, e.g. methyl. In embodiments, R¹¹ is at each occurrence C₁-C₄-alkyl, e.g. methyl.

In embodiments, L¹, L², L³, L⁴, L⁵ and n are selected such that length of the linker formed by those groups is from 8 to 14 atoms.

In embodiments, Z¹ is

and Z² is R^(4b).

In embodiments, L¹ is selected from —C(O)— and —S(O)₂—. In embodiments, L¹ is —C(O)—.

In embodiments, L¹ is absent.

In certain embodiments, L³ is at each occurrence absent. Thus, the group -L²-(L³-L⁴)_(n)- may form an alkylene linker group.

In certain embodiments, L³ is at each occurrence —O— and -L⁴- is at each occurrence —C₂-C₄-alkylene-. Thus, the group -(L³-L⁴)_(n)- may form a ether or polyether linker group. -L⁴- may at each occurrence represent —CH₂CH₂— or —CH₂CH₂CH₂—. Thus, the group -(L³-L⁴)_(n)- may form a, ethylene glycol, polyethyleneglycol, propyleneglycol or polypropylene glycol linker group.

In certain embodiments, L³ is at each occurrence —NR⁵C(O)—, —C(O)NR⁵. Thus, the group -(L³-L⁴)_(n)- may form a peptide linker group. In these embodiments, it may be that -L⁴- is at each occurrence —C₁-alkylene-.

In embodiments, L¹, L², L³, L⁴ and n are selected such that length of the linker formed by those groups is from 8 to 14 atoms.

In embodiments Z¹ is:

wherein L⁶ is a C₂-C₁₅-alkylene group optionally substituted with from 0 to 10 R³ groups. L may be a C₇-C₁₃-alkylene group optionally substituted with from 0 to 10 R⁸ groups. L⁶ may be unsubstituted.

In specific embodiments, -L¹-L²-(L³-L⁴-)_(n) represents —C(O)(CH₂)₁₁—, —C(O)(CH₂)₁₀—, —C(O)(CH₂)₉—, —C(O)(CH₂)₃—, —C(O)(CH₂)₇—, —C(O)(CH₂)₆—, or —C(O)(CH₂)₅—.

In specific embodiments, -L¹-L²-(L³-L⁴)_(n)- represents —C(O)NH(CH₂)₃—, —C(O)NH(CH₂)₇—, or —C(O)NH(CH₂)₆—.

In embodiments Z¹ is:

wherein L⁷ is a C₃-C₁₆-alkylene group optionally substituted with from 0 to 10 R³ groups. L⁷ may be a C₈-C₁₄-alkylene group optionally substituted with from 0 to 10 R³ groups. L⁷ may be unsubstituted.

In embodiments, L⁵ is absent.

In embodiments, L⁵ is —C(O)—.

In embodiments, L⁵ is —C(O)NR⁵—, e.g. —C(O)NH—.

In certain embodiments, L³ is at each occurrence absent. Thus, the group -L²-(L³-L⁴)_(n)- may form an alkylene linker group.

In certain embodiments, L³ is at each occurrence —O— and -L⁴- is at each occurrence —C₂-C₄-alkylene-. Thus, the group -(L³-L⁴)_(n)- may form a ether or polyether linker group. -L⁴- may at each occurrence represent —CH₂CH₂— or —CH₂CH₂CH₂—. Thus, the group -(L³-L⁴)_(n)- may form a, ethylene glycol, polyethyleneglycol, propyleneglycol or polypropylene glycol linker group.

In certain embodiments, L³ is at each occurrence —NR⁵C(O)—, —C(O)NR⁵. Thus, the group -(L³-L⁴)_(n)- may form a peptide linker group. In these embodiments, it may be that -L⁴- is at each occurrence —C₁-alkylene-.

In embodiments, L⁵, L², L³, L⁴ and n are selected such that length of the linker formed by those groups is from 8 to 14 atoms.

In embodiments Z² is:

wherein L⁸ is a C₂-C₁₃-alkylene group optionally substituted with from 0 to 10 R³ groups. L³ may be a C₅-C₁-alkylene group optionally substituted with from 0 to 10 R³ groups. L may be unsubstituted.

In embodiments of Z², -L⁵-L²-(L³-L⁴)_(n)- represents —C(O)NH(CH₂)₁₀—, —C(O)NH(CH₂)₃—, —C(O)NH(CH₂)₆—, —C(O)NH(CH₂)₁₁—, —C(O)NH(CH₂)₉—, —C(O)NH(CH₂)₇—, or —C(O)NH(CH₂)₅—.

In embodiments of Z², -L⁵-L²-(L³-L⁴)_(n)- represents —C(O)NH(CH₂)₁₀—, —C(O)NH(CH₂)₃—, or —C(O)NH(CH₂)₆—.

In embodiments the ion of formula (I) is an ion of formula (IIa):

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, 5- or 6-membered heteroaryl and C₃ to C₈-cycloalkyl, wherein said phenyl, biphenyl and 5- or 6-membered heteroaryl is optionally substituted with from 1 to 5 independently selected R^(1d) groups, and wherein said C₃ to C₈-cycloalkyl is optionally substituted with from 1 to 5 independently selected R^(1e) groups; provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, pyridyl and cyclohexyl, wherein said phenyl, biphenyl and pyridyl is optionally substituted with from 1 to 5 independently selected R^(1d) groups, and wherein said cyclohexyl group is optionally substituted with from 1 to 5 independently selected R^(1e) groups; provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, pyridyl and cyclohexyl, wherein said phenyl, biphenyl and pyridyl is optionally substituted with 1 to 3 independently selected R^(1d) groups, and wherein said cyclohexyl group is optionally substituted with 1 to 3 independently selected R^(1e) groups; provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl; wherein said phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl is optionally substituted with from 1 to 5 independently selected R^(1d) groups, provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, optionally substituted with from 1 to 5 independently selected R^(1d) groups, provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl; wherein said phenyl is optionally substituted with from 1, 2 or 3 independently selected R^(1d) groups, provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl; wherein said phenyl is optionally substituted with from 1, 2 or 3 R^(1d) groups; provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from C₃ to C₈ cycloalkyl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl; wherein said C₃ to C₈ cycloalkyl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl is optionally substituted with from 1 to 5 independently selected R^(1e) groups.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from C₃ to C₈ cycloalkyl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl; wherein said C₃ to C₈ cycloalkyl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl is optionally substituted with from 1 to 5 independently selected R^(1e) groups.

In embodiments R^(1a), R^(1b) and R^(1c) are different or the same.

In embodiments, R^(1e) is independently at each occurrence selected from C₁-C₆-alkyl, halo, OR⁹, NR¹⁰R¹¹ and S(O)₂OR¹⁰.

In embodiments, R^(1e) is independently at each occurrence selected from OCH₃, OCH₂(CH₃)₂, N(CH₃)₂, SO₂OH, F and Cl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, pyridyl and cyclohexyl, wherein said phenyl, biphenyl and pyridyl is optionally substituted with 1 to 3 independently selected R^(1d) groups, wherein R^(1d) is independently at each occurrence selected from C₁-C₆-alkyl, halo, OR⁹, NR¹⁰R¹¹ and S(O)₂OR¹⁰.

In embodiments, R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, pyridyl and cyclohexyl, wherein said phenyl, biphenyl and pyridyl is optionally substituted with 1 to 3 independently selected R^(1d) groups, wherein R^(1d) is independently at each occurrence selected from OCH₃, OCH₂(CH₃)₂, N(CH₃)₂, SO₂OH, F and Cl.

In embodiments, R^(1a) is C₃ to C₈-cycloalkyl, R^(1b) is C₃ to C₈-cycloalkyl and R^(1c) is C₃ to C₈-cycloalkyl.

In embodiments, R^(1a) and R^(1b) are each unsubstituted phenyl and R^(1c) is independently selected from: substituted phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl.

In embodiments, R^(1a) and R^(1b) are each unsubstituted phenyl and R^(1c) is independently selected from: substituted phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl.

In embodiments, R^(1a) and R^(1b) are each unsubstituted phenyl and R^(1c) is substituted phenyl.

In embodiments, R^(1a) and R^(1b) are each unsubstituted phenyl and R^(1c) is pyridyl.

In embodiments, R^(1a) and R^(1b) are each C₃ to C₈-cycloalkyl and R^(1c) is independently selected from: phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl.

In embodiments, R^(1a) and R^(1b) are each C₃ to C₈-cycloalkyl and R^(1c) is independently selected from: phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl.

In embodiments, R^(1a) and R^(1b) are each cyclohexyl and R^(1c) is substituted biphenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each substituted phenyl. It may be that R^(1a), R^(1b) and R^(1c) are each fluorophenyl, e.g. para-fluorophenyl. It may be that R^(1a), R^(1b) and R^(1c) are each chlorophenyl, e.g. para-chlorophenyl. It may be that R^(1a), R^(1b) and R^(1c) are each methoxyphenyl, e.g. para-methoxyphenyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each C₃ to C₈-cycloalkyl. In embodiments, R^(1a), R^(1b) and R^(1c) are each cyclohexyl.

In embodiments, R^(1a), R^(1b) and R^(1c) are each benzyl.

In embodiments, at least one of R^(1a), R^(1b) and R^(1c) is 5-, 6-, 9- or 10-membered heteroaryl or 4- to 8-membered heterocycloalkyl. It may be that a single one of R^(1a), R^(1b) and R^(1c) is 5-, 6-, 9- or 10-membered heteroaryl or 4- to 8-membered heterocycloalkyl. In embodiments, at least one of R^(1a), R^(1b) and R^(1c) is 5-, 6-, 9- or 10-membered heteroaryl or 4- to 8-membered heterocycloalkyl, wherein said heteroaryl or heterocycloalkyl group comprises at least one nitrogen atom in the ring. It may be that a single one of R^(1a), R^(1b) and R^(1c) is 5-, 6-, 9- or 10-membered heteroaryl or 4- to 8-membered heterocycloalkyl, wherein said heteroaryl or heterocycloalkyl group comprises at least one nitrogen atom in the ring. In embodiments, at least one of R^(1a), R^(1b) and R^(1c) is 5- or 6-membered heteroaryl group, wherein said heteroaryl group comprises at least one nitrogen atom in the ring. It may be that a single one of R^(1a), R^(1b) and R^(1c) is 5- or 6-membered heteroaryl group, wherein said heteroaryl group comprises at least one nitrogen atom in the ring. In these embodiments, it may be that any of Ria, R^(1b) and R^(1c) that are not heteroaryl or heterocyclolkyl are phenyl, e.g. unsubstituted phenyl.

In embodiments, at least one of R^(1a), R^(1b) and R^(1c) is 5-, 6-, 9- or 10-membered heteroaryl or 5- to 8-membered heterocycloalkyl. It may be that a single one of R^(1a), R^(1b) and R^(1c) is 5-, 6-, 9- or 10-membered heteroaryl or 5- to 8-membered heterocycloalkyl. In embodiments, at least one of R^(1a), R^(1b) and R^(1c) is 5-, 6-, 9- or 10-membered heteroaryl or 5- to 8-membered heterocycloalkyl, wherein said heteroaryl or heterocycloalkyl group comprises at least one nitrogen atom in the ring. It may be that a single one of R^(1a), R^(1b) and R^(1c) is 5-, 6-, 9- or 10-membered heteroaryl or 5- to 8-membered heterocycloalkyl, wherein said heteroaryl or heterocycloalkyl group comprises at least one nitrogen atom in the ring. In embodiments, at least one of R^(1a), R^(1b) and R^(1c) is 5- or 6-membered heteroaryl group, wherein said heteroaryl group comprises at least one nitrogen atom in the ring. It may be that a single one of R^(1a), R^(1b) and R^(1c) is 5- or 6-membered heteroaryl group, wherein said heteroaryl group comprises at least one nitrogen atom in the ring. In these embodiments, it may be that any of Ria, R^(1b) and R^(1c) that are not heteroaryl or heterocyclolkyl are phenyl, e.g. unsubstituted phenyl.

In embodiments, at least one of R^(1a), R^(1b) and R^(1c) is C₁-C₆-alkyl (e.g. methyl). It may be that a single one of R^(1a), R^(1b) and R^(1c) is C₁-C₆-alkyl (e.g. methyl). It may be that two or more of R^(1a), R^(1b) and R^(1c) is C₁-C₆-alkyl (e.g. methyl). It may be that each of R^(1a), R^(1b)and R^(1c) is C₁-C₆-alkyl (e.g. methyl). In these embodiments, it may be that any of R^(1a), R^(1b) and R^(1c) that are not C₁-C₆-alkyl are phenyl, e.g. unsubstituted phenyl.

It may be that R^(1a) and R^(1b) are connected to each other via a bond or a group selected from —O—, NR^(6a), and C₁-C₃-alkylene. It may be that R^(1a) and R^(1b) are connected to each other via a bond or a C₁-C₃-alkylene group. It may be that R^(1a) and R^(1b) are connected to each other via a bond. It may be that R^(1a) and R^(1b) are each phenyl and are connected to each other via a bond or a group selected from —O—, NR^(6a), and C₁-C₃-alkylene. It may be that R^(1a) and R^(1b) are each phenyl and are connected to each other via a bond or a C₁-C₃-alkylene group. It may be that R^(1a) and R^(1b) are each phenyl and are connected to each other via a bond.

It may be that R^(1a) and R^(1b) are not connected to each other via a bond or a group selected from —O—, NR^(6a), and C₁-C₃-alkylene.

In embodiments, —⁺PR^(1a)R^(1b)R^(1c) is selected from:

In an embodiment of the invention the ion of formula (I) is a formula selected from:

In an embodiment of the invention the ion of formula (I) is a formula selected from:

The cation of formula (I) will be associated with an anionic counter ion. For administration to a subject, the cation of formula (I) will be associated with a pharmaceutically acceptable anionic counterion. The first aspect of the invention also, therefore, provides a compound comprising the ion of formula (I) and a pharmaceutically acceptable anion. The anion may have a single negative charge. For example the anion may be selected from: halo (e.g. Cl, Br and I), BF₄, PFe, CF₃C(O)O, HC(O)O, HCO₃, (CF₃SO₂)₂N, (C₂F₅)₃PF₃, HSO₄, C₁-C₁₅-alkylSO₄, CH₃C(O)O, CF₃SO₃, Tosyl-O, C(CN)₃, N(CN)₂ or the carboxylate anion of a proteinogenic amino acid. For the avoidance of doubt each anion listed in the preceding sentence possesses a single negative charge. The anion may have multiple negative charges, e.g. PO₄ ³⁻ or CO₃ ²⁻. The anion may be derived from a di- or tri-acid, e.g. glutamic acid, succinic acid, malic acid, citric acid, tartaric acid. It may be a mono-carboxylate of said di- or tri-acid. The remaining carboxylic acid groups may be in the form of protonated carboxylic acids, C₁-C₁₂-alkylesters, or they may likewise be carboxylate anions. Said carboxylate anions may each be accompanied by a pharmaceutically acceptable metal cation or by another cation of formula (I).

The anions associated with the cations of the invention can be quite labile. It may be therefore that the cation of the invention is present associated with two or more different anions. Ion exchange processes can be used to control the identity of the anion associated with the cation of the invention.

In embodiments the anion is Cl, Br, I, PF₆, CF₃C(O)O, or HC(O)O.

In an aspect of the invention, the compounds of the invention are for medical use.

In an aspect the compounds of the first aspect of the invention are for use in the treatment of cancer. The compounds may also be for use in reducing cell proliferation of abnormal cells, such as cancer cells.

In an embodiment the compounds of the first aspect of the invention are for use in the treatment of solid tumours and other cancers, e.g. cancers classed as not being solid cancers. Amongst cancers that can be treated by the compounds of the invention are: leukaemia, lymphoma, sarcoma, or carcinoma.

In a further aspect of the invention there is provided a method for the treatment of cancer, wherein the method comprises the administration of a therapeutically effective amount of a compound of the first aspect of the invention. The method may also be for use in reducing cell proliferation of abnormal cells, such as cancer cells.

In an embodiment the method is for the treatment of solid tumours and other cancers, e.g. cancers classed as not being solid cancers. Amongst cancers that can be treated by the methods of the invention are: leukaemia, lymphoma, sarcoma, or carcinoma.

The “treatment” of cancer may be taken to include prevention. Treatment also encompasses including any improvement of pathology, symptoms or prognosis that is achieved in respect of cancer in a subject receiving compounds of the invention. Treatment may be indicated by a partial improvement of such indications, or by a total improvement (e.g. the absence of cancer following medical use of the compounds of the invention).

The “prevention” of cancer may be taken as including the prevention of the formation of new tumours, including new primary tumours or new metastatic tumours. The prevention of cancer may also be taken as encompassing the prevention of the progression of cancer. In this context, prevention of development of cancer may be demonstrated by preventing an increase in the “stage” of a tumour (using an appropriate cancer staging method) that has been treated using the compounds of the invention. The prevention of increase in cancer stage may be compared to progression of an untreated tumour, or compared to the extent of progression that would be expected by a clinician in the event that the tumour was not treated.

The compounds of the first aspect of the invention may be for use in increasing cancer cell death or for decreasing cell proliferation by another mechanism, such as inhibiting cell replication. The compounds may be used for this purpose in vitro or in vivo.

The compounds of the invention may be for use in the modulation of cancer cells or other dysfunctional cells (such as tumour initiating cells, stem-like cancer cells, cancer stem cells, or a population of cells with stem cell-like features that exist in tumors and that give rise to the bulk of tumor cells with more differentiated phenotypes). Accordingly, there is provided a method of modulating cancer cells or other dysfunctional cells in vivo or in vitro by exposing the cancer cells or other dysfunctional cells to a compound of the first aspect of the invention. The compound may be exposed to the cancer cells or other dysfunctional cells in an effective amount, for example a therapeutically effective amount such as in the case of a method of treatment or an in vivo method.

In another aspect of the invention there is provided a pharmaceutical composition, wherein the composition comprises a compound of the invention and one or more pharmaceutically acceptable excipients.

In an embodiment the pharmaceutical composition may be a combination product comprising one or more different pharmaceutically active agents. The one or more additional pharmaceutically active agents may be an anti-cancer agent described below.

The one or more pharmaceutically active agents may independently be selected from a different therapeutic class, e.g. antibiotic, anti-viral, anti-emetic, pain management, etc.

The present invention contemplates the following numbered clauses:

1. A compound comprising an ion of formula (I) or a pharmaceutically acceptable salt thereof:

wherein either Z¹ is

and Z² is R^(4b); or Z² is

and Z¹ is R^(2b); Z³ is independently selected from H, C(O)—C₁-C₆-alkyl or Z³ has the structure:

Z⁴ is independently selected from H, C(O)—C₁-C₆-alkyl or Z⁴ has the structure:

-L¹- is independently absent or is selected from —C(O)—, —C(O)O—, —S(O)₂—, —S(O)—, —C(O)NR⁵, and —S(O)₂NR⁵—; -L³- is independently at each occurrence either absent or selected from: —O—, —S—, —NR⁶—, —C(O)—, —OC(O)—, —C(O)O—, —S(O)₂—, —S(O)—, —NR⁵C(O)—, —C(O)NR⁵, —NR⁵S(O)₂—, —S(O)₂NR⁵—, —OC(O)NR⁵—, —NR⁵C(O)O—, NR⁵C(O)NR⁵, —CR⁷═CR⁷— and —C≡C—; -L²- and -L⁴- are each independently at each occurrence —C₁-C₄-alkylene-, each alkylene group being unsubstituted or substituted with from 1 to 6 independently selected R⁸ groups; provided that any -L₂- or -L₄- group that is attached at each end to an atom selected from oxygen, nitrogen, sulphur or phosphorous is —C₂-C₄-alkylene-; -L⁵- is independently absent or is selected from: —C(O)— and —C(O)NR⁵—; n is an integer selected from 0, 1, 2, 3, 4 and 5; wherein L¹, L², L³, L⁴, L⁵ and n are selected such that length of the linker formed by those groups is from 3 to 16 atoms; R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl; wherein said phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl is optionally substituted with from 1 to 5 independently selected R^(1d) groups; and wherein said C to C-cycloalkyl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl is optionally substituted with from 1 to 5 independently selected R^(1e) groups; provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl; R^(1d) is independently at each occurrence selected from: C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, 5- to 8-membered heterocycloalkyl, 5-, 6-, 9- or 10-membered heteroaryl, phenyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R^(1e) is independently at each occurrence selected from: oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, 5- to 8-membered heterocycloalkyl, 5-, 6-, 9- or 10-membered heteroaryl, phenyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R^(2a), R^(2b) and R^(2c) are each independently selected from H and C₁-C₆-alkyl; R^(3a) is independently selected from: H, C₁-C₆-alkyl and C(O)—C₁-C₆-alkyl; R^(3b) and R^(3c) are each independently selected from: H and C(O)—C₁-C₆-alkyl; R^(4a) and R^(4b) are each independently selected from: H, C₁-C₆-alkyl and C(O)—C₁-C₆-alkyl; or R^(4a) and R^(4b) taken together form C(O); R⁵ is independently at each occurrence selected from H and C₁-C₆-alkyl; R⁶ and R¹¹ are each independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl; R⁷ is independently at each occurrence selected from H, C₁-C₄-alkyl and halo; R⁸ is independently at each occurrence selected from: C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)₂R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R⁹ is independently at each occurrence selected from: H, C₁-C₆-alkyl and C₁-C₆-haloalkyl; R¹⁰ is independently at each occurrence selected from: H and C₁-C₆-alkyl; and wherein any of the abovementioned alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, heteroaryl or phenyl groups is optionally substituted where chemically allowable by from 1 to 4 groups independently selected from oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, OR^(a), NR^(a)R^(b), SR^(a), C(O)OR^(a), C(O)NR^(a)R^(a), halo, cyano, nitro, C(O)R^(a), S(O)₂OR^(a), S(O)₂R^(a), S(O)R^(a) and S(O)₂NR^(a)R^(a); wherein R^(a) is independently at each occurrence selected from: H and C₁-C₆-alkyl; and R^(b) is independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl. 2. A compound of clause 1, wherein Z¹ is

and Z² is R^(4b). 3. A compound of clause 2, wherein L¹ is selected from —C(O)— and —S(O)₂—. 4. A compound of clause 2, wherein L¹ is absent. 5. A compound of any one of clauses 2 to 4, wherein R^(4a) is H and R^(4b) is H. 6. A compound of any one of clauses 2 to 4, wherein R^(4a) and R^(4b) together form C(O). 7. A compound of clause 1, wherein Z² is

and Z¹ is R^(2b), preferably wherein R^(2b) is methyl. 8. A compound of clause 7, wherein L⁵ is —C(O)—. 9. A compound of clause 7, wherein L⁵ is —C(O)NR⁵—. 10. A compound of any one of clauses 7 to 9, wherein R^(4a) is H. 11. A compound of any one of clauses 1 to 10, wherein L³ is at each occurrence absent. 12. A compound of any one of clauses 1 to 11, wherein L¹, L², L³, L⁴, L⁵ and n are selected such that length of the linker formed by those groups is from 8 to 14 atoms. 13. A compound of any one of clauses 1 to 12, wherein Z³ is

preferably wherein R^(3c) is H. 14. A compound of any one of clauses 1 to 13, wherein R^(2a) is methyl and R^(2c) is methyl. 15. A compound of any one of clauses 1 to 14, wherein R^(3a) is H and R^(3b) is H. 16. A compound of any one of clauses 1 to 14, wherein R^(3a) is H and R^(3b) is C(O)CH₃. 17. A compound of any one of clauses 1 to 16, wherein R^(1a), R^(1b) and R^(1c) are each substituted phenyl. 18. A compound of any one of clauses 1 to 16, wherein R^(1a), R^(1b) and R^(1c) are each C₃ to C₈-cycloalkyl. 19. A compound of any one of clauses 1 to 16, wherein R^(1a), R^(1b) and R^(1c) are each benzyl. 20. A compound of any one of clauses 1 to 16, wherein R^(1a) and R^(1b) are each unsubstituted phenyl and R^(1c) is independently selected from: substituted phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl. 21. A compound of any one of clauses 1 to 16, wherein R^(1a) and R^(1b) are each C₃ to C₈-cycloalkyl and R^(1c) is independently selected from: phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₁-C₈-alkyl and 5- to 8-membered heterocycloalkyl. 22. A compound of any one of clauses 1 to 16, wherein at least one of R^(1a), R^(1b) and R^(1c) is C₁-C₆-alkyl. 23. A compound of clause 22, wherein any of R^(1a), R^(1b) and R^(1c) that are not C₁-C₆-alkyl are phenyl. 24. A compound of any one of clauses 1 to 23, wherein the compound is for medical use. 25. A compound of any one of clauses 1 to 23, wherein the compound is for use in the treatment of cancer. 26. A method for the treatment of cancer, wherein the method comprises the administration of a therapeutically effective amount of a compound of any one of clauses 1 to 23. 27. A pharmaceutical composition, wherein the composition comprises a compound of any one of clauses 1 to 23 and one or more pharmaceutically acceptable excipients.

DETAILED DESCRIPTION

Given below are definitions of terms used in this application. Any term not defined herein takes the normal meaning as the skilled person would understand the term.

The term “halo” or “halogen” refers to an atom selected from fluorine, chlorine, bromine and iodine. “Halo” or “halogen” may refer to an atom selected from C₁ and F. “Halo” or “halogen” may refer to fluorine.

The term “alkyl” refers to a linear or branched hydrocarbon chain. The term “C₁-C₈ alkyl” refers to a linear or branched hydrocarbon chain containing 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms. The term “C₁-C₆ alkyl” refers to a linear or branched hydrocarbon chain containing 1, 2, 3, 4, 5 or 6 carbon atoms. The term “C₁-C₆ alkyl” for example refers to methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl and n-hexyl. The “alkyl” group may be substituted or unsubstituted by one or more substituents. Substituents for the alkyl group may be halo (for example fluorine, chlorine, bromine and iodine), OH and C₁-C₆ alkoxy. In addition, alkylene groups may be linear or branched and may have two places of attachment to the remainder of the molecule.

The term “alkylene” refers to a divalent group which is a linear or branched hydrocarbon chain. With the “alkylene” group being divalent, the group must form two bonds to other groups. The term “C₁-C₈-alkylene” may refer to —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂— or substituted equivalents thereof. The alkylene group may be unsubstituted or substituted by one or more substituents.

The term “cycloalkyl” refers to a saturated hydrocarbon ring system. The term “C₃-C₈ cycloalkyl” refers to a saturated hydrocarbon ring system containing 3, 4, 5, 6, 7 or 8 carbon atoms. The ring system may be a single ring or a bi-cyclic or tri-cyclic ring system. Where the ring system is bicyclic one of the rings may be an aromatic ring, for example as in indane. The term “cycloalkyl” may refer to, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and indane. The cycloalkyl group may be substituted with one or more substituents.

The term “haloalkyl” refers to a linear or branched hydrocarbon chain which is substituted with at least one halogen atom which are independently selected at each occurrence from fluorine, chlorine, bromine and iodine. For example, the term “C₁-C₆ haloalkyl” refers to a linear or branched hydrocarbon chain containing 1, 2, 3, 4, 5 or 6 carbon atoms. The halogen atom may be at substituted at any position on the hydrocarbon chain. The term “C₁-C₆ haloalkyl” may refer to, for example, fluoromethyl, trifluoromethyl, chloromethyl, fluoroethyl, trifluoroethyl, chloroethyl, trichloroethyl (such as 1,2,2-trichloroethyl and 2,2,2-trichloroethyl), fluoropropyl and chloropropyl. The haloalkyl group may be substituted with one or more substituents.

The term “alkenyl” refers to a linear or branched hydrocarbon chain containing at least one carbon-carbon double bond and having at least two carbon atoms. The term “C₂-C₆ alkenyl” refers to a linear or branched hydrocarbon chain containing at least one carbon-carbon double bond and having 2, 3, 4, 5 or 6 carbon atoms. The double bond or double bonds may be E or Z isomers. The double bond may be present at any possible position of the hydrocarbon chain. The term “C₂-C₆ alkenyl” may refer to, for example, ethenyl, propenyl, butenyl, butadienyl, pentenyl, pentadienyl, hexenyl and hexadienyl. The alkenyl group may be substituted or unsubstituted by one or more substituents.

The term “cycloalkenyl” refers to an unsaturated hydrocarbon ring system. The term “C₃-C₈ cycloalkenyl” refers to an unsaturated hydrocarbon ring system containing 3, 4, 5, 6, 7 or 8 carbon atoms. The ring may contain more than one double bond. The term cycloalkenyl may refer to, for example cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclohexadienyl, cycloheptenyl, cycloheptadiene, cyclooctenyl and cycloocatadienyl. The cycloalkenyl group may be substituted with one or more substituents.

The term “alkynyl” refers to a linear or branched hydrocarbon chain contain at least one carbon-carbon triple bond and having at least two carbon atoms. The term “C₂-C₆ alkynyl” refers to a linear or branched hydrocarbon chain containing at least one carbon-carbon triple bond and having 2, 3, 4, 5 or 6 carbon atoms. The triple bond or triple bonds may be present at any possible position of the hydrocarbon chain. The term “C₂-C₆ alkynyl” may refer to, for example, ethynyl, propynyl, butynyl, pentynyl and hexynyl. The alkynyl group may be unsubstituted or substituted by one or more substituents.

The term “heteroalkyl” refers to a linear or branched hydrocarbon chain containing at least one heteroatom selected from N, O and S which is positioned between any possible carbon atom in the chain or at the end of the chain. The term “C₁-C₆ heteroalkyl” refers to a linear or branched hydrocarbon chain containing 1, 2, 3, 4, 5, or 6 carbon atoms and at least one heteroatom selected from N, O and S which is positioned between any possible carbon atom in the chain or at the end of the chain. The heteroalkyl may be attached to another group by the heteroatom or the carbon atom. The term “C₁-C₆ heteroalkyl” may refer to, for example, —CH₂NHCH₃, —NHCH₂CH₃ and —CH₂CH₂NH₂. The heteroalkyl group may be unsubstituted or substituted by one or more substituents.

The term “heterocycloalkyl” refers to a saturated hydrocarbon ring system containing at least one heteroatom within the ring system selected from N, O and S. The term “5- to 8-membered heterocycloalkyl” refers to a saturated hydrocarbon ring with 5, 6, 7, 8, 9 or 10 atoms selected from carbon, N, O and S, at least one being a heteroatom. The “heterocycloalkyl” group may also be denoted as a “3 to 10 membered heterocycloalkyl” which is also a ring system containing 3, 4, 5, 6, 7, 8, 9 or 10 atoms, at least one being a heteroatom. The ring system may be a single ring or a bi-cyclic or tri-cyclic ring system. Bicyclic systems may be spiro-fused, i.e. where the rings are linked to each other through a single carbon atom; vicinally fused, i.e. where the rings are linked to each other through two adjacent carbon or nitrogen atoms; or they may be share a bridgehead, i.e. the rings are linked to each other two non-adjacent carbon or nitrogen atoms. Where the ring system is bicyclic one of the rings may be an aromatic ring, for example as in chromane. The “heterocycloalkyl” may be bonded to the rest of the molecule through any carbon atom or heteroatom. The “heterocycloalkyl” may have one or more, e.g. one or two, bonds to the rest of the molecule: these bonds may be through any of the atoms in the ring. For example, the “heterocycloalkyl” may be oxirane, aziridine, azetidine, oxetane, tetrahydrofuran, pyrrolidine, imidazolidine, succinimide, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine, piperidine, morpholine, thiomorpholine, piperazine, tetrahydropyran, and chromane.

The term “heterocycloalkenyl” refers to an unsaturated hydrocarbon ring system containing at least one heteroatom selected from N, O or S. The term “C₃-C₈ heterocycloalkenyl” refers to an unsaturated hydrocarbon ring system containing 3, 4, 5, 6, 7 or 8 carbon atoms and at least one heteroatom selected from N, O or S. There may be more than one double bond present. The double bond will typically be between two carbon atoms but may be between a carbon atom and a nitrogen atom. There may also be more than 1 heteroatom present. For example, there may be 1, 2 or 3 heteroatoms present. The ring system may be a single ring or a bi-cyclic or tri-cyclic ring system. Where the ring system is bicyclic one of the rings may be an aromatic ring, for example as in indoline and dihydrobenzofuran. The heterocycloalkenyl may be attached to another group by any carbon or heteroatom. The term heterocycloalkenyl may refer to, for example tetrahydropyridine, dihydropyran, dihydrofuran, pyrroline, dihydrobenzofuran, dihydrobenzothiophene and indoline. The heterocycloalkenyl group may be substituted with one or more substituents.

The term “aryl” refers to an aromatic hydrocarbon ring system which satisfies Huckel's rule for aromaticity or that contains a ring system which satisfies Huckel's rule for aromaticity. As such an aryl group may be a single ring or a bi-cyclic or tri-cyclic ring system. The term “aryl” may refer to, for example, phenyl, naphthyl, indane, tetralin and anthracene. The aryl group may be unsubstituted or substituted with one or more substituents. Any aryl group may be a phenyl ring.

The term “heteroaryl” refers to an aromatic hydrocarbon ring system with at least one heteroatom selected from N, O or S which satisfies Huckel's rule for aromaticity or a ring system that contains a heteroatom and an aromatic hydrocarbon ring. The heteroaryl may be a single ring system or a fused ring system. The term “5-, 6-, 9- or 10-membered heteroaryl” refers to an aromatic ring system within 5, 6, 9, or 10 members selected from carbon, N, O or S either in a single ring or a bicyclic ring system. The term heteroaryl may refer to, for example, imidazole, thiazole, oxazole, isothiazole, isoxazole, triazole, tetraazole, thiophene, furan, thianthrene, pyrrole, benzimidazole, pyrazole, pyrazine, pyridine, pyrimidine, indole, isoindole, quinolone, and isoquinoline.

The term “alkoxy” refers to an alkyl group which is linked to another group by oxygen. The alkyl group may be linear or branched. The term “C₁-C₆ alkoxy” refers to an alkyl group containing 1, 2, 3, 4, 5 or 6 carbon atoms which is linked to another group by oxygen. The alkyl group may be, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl and n-hexyl. The term “C₁-C₆ alkoxy” may refer to, for example, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy and n-hexoxy. The alkyl group may be substituted or unsubstituted by one or more substituents.

A bond terminating in a “

” means that the bond is connected to another group that is not shown. A bond terminating inside a cyclic structure and not terminating at an atom of the ring structure represents that the bond may be connected to any of the atoms in the ring structure where allowed by valency.

Where a group is substituted, it may be substituted at any point on the group where chemically possible and consistent with valency requirements. The group may be substituted by one or more substituents. For example, the group may be substituted with 1, 2, 3 or 4 substituents. Where there are two or more substituents, the substituents may be the same or different. Substituent(s) may be, for example, halo, CN, nitro, oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁—C-haloalkyl, OR^(a), NR^(a)R^(b), SR^(a), C(O)OR^(a), C(O)NR^(a)R^(a), halo, cyano, nitro, C(O)R^(a), S(O)₂OR^(a), S(O)₂R^(a) and S(O)₂NR^(a)R^(a); wherein R^(a) is independently at each occurrence selected from: H and C₁-C₆-alkyl; and R^(b) is independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl.

If chemically possible to do so, a cyclic substituent may be substituted on a group so as to form a spiro-cycle.

Substituents are only present at positions where they are chemically possible, the person skilled in the art being able to decide (either experimentally or theoretically) without inappropriate effort which substitutions are chemically possible and which are not.

Ortho, meta and para substitution are well understood terms in the art. For the absence of doubt, “ortho” substitution is a substitution pattern where adjacent carbons possess a substituent, whether a simple group, for example the fluoro group in the example below, or other portions of the molecule, as indicated by the bond ending in “

”.

“Meta” substitution is a substitution pattern where two substituents are on carbons one carbon removed from each other, i.e with a single carbon atom between the substituted carbons. In other words there is a substituent on the second atom away from the atom with another substituent. For example the groups below are meta substituted.

“Para” substitution is a substitution pattern where two substituents are on carbons two carbons removed from each other, i.e with two carbon atoms between the substituted carbons. In other words there is a substituent on the third atom away from the atom with another substituent. For example the groups below are para substituted

The cation of formula (I) will be associated with a pharmaceutically acceptable anionic counter ion for administration to a subject. Nevertheless, where either the cation of formula (I) or the anionic counter ion comprise either basic or acidic groups, those groups may themselves be protonated or deprotonated and associated with an appropriate counter ion.

Suitable acid addition salts are formed from acids which form non-toxic salts, for example, acetate, aspartate, benzoate, besylate, bicarbonate/carbonate, bisulphate/sulphate, borate, camsylate, citrate, edisylate, esylate, formate, fumarate, gluceptate, gluconate, glucuronate, hexafluorophosphate, hibenzate, hydrochloride/chloride, hydrobromide/bromide, hydroiodide/iodide, isethionate, lactate, malate, maleate, malonate, mesylate, methylsulphate, naphthylate, 1,5-naphthalenedisulfonate, 2-napsylate, nicotinate, nitrate, orotate, oxalate, palmitate, pamoate, phosphate/hydrogen phosphate/dihydrogen phosphate, saccharate, stearate, succinate, tartrate, tosylate and trifluoroacetate salts.

Suitable base salts are formed from bases which form non-toxic salts, for example including the aluminium, arginine, benzathine, calcium, choline, diethylamine, diolamine, glycine, lysine, magnesium, meglumine, olamine, potassium, sodium, tromethamine and zinc salts. Hemisalts of acids and bases may also be formed, for example, hemisulphate and hemicalcium salts. A review of suitable salts can be found in “Handbook of Pharmaceutical Salts: Properties, Selection, and Use” by Stahl and Wermuth (Wiley-VCH, Weinheim, Germany, 2002).

The salt may be an acid addition salt.

The salts may be formate or hydrochloride.

Pharmaceutically acceptable salts of compounds of formula (I) may be prepared by one or more of the following methods:

(i) reacting the compound of formula (I) with the desired acid or base;

(ii) removing an acid- or base-labile protecting group from a suitable precursor of the compound of formula (I) or by ring-opening a suitable cyclic precursor, for example, a lactone or lactam, using the desired acid or base; or

(iii) converting one salt of the compound of formula (I) to another by reaction with an appropriate acid or base or by means of a suitable ion exchange column.

The reactions above are typically carried out in solution and the resulting salt may precipitate out and be collected by filtration or may be recovered by evaporation of the solvent. The degree of ionisation in the resulting salt may vary from completely ionised to almost non-ionised.

The compounds may exist in both unsolvated and solvated forms. The term ‘solvate’ is used herein to describe a molecular complex comprising the compound of the invention and a stoichiometric amount of one or more pharmaceutically acceptable solvent molecules, for example, ethanol. The term ‘hydrate’ is employed when said solvent is water.

Complexes are contemplated, such as clathrates, drug-host inclusion complexes wherein, in contrast to the aforementioned solvates, the drug and host are present in stoichiometric or non-stoichiometric amounts. Complexes of the drug containing two or more organic and/or inorganic components which may be in stoichiometric or non-stoichiometric amounts are also contemplated. The resulting complexes may be ionised, partially ionised, or non-ionised. A review of such complexes is found in J Pharm Sci, 64 (8), 1269-1288 by Haleblian (August 1975).

Compounds and salts described in this specification may be isotopically-labelled (or “radio-labelled”). Accordingly, one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number typically found in nature. Examples of radionuclides that may be incorporated include ²H (also written as “D” for deuterium), ³H (also written as “T” for tritium), ¹¹C, ¹³C, ¹⁴C, ¹⁵O, ¹⁷O, ¹⁸O, ¹⁸F and the like. The radionuclide that is used will depend on the specific application of that radio-labelled derivative. For example, for in vitro competition assays, ³H or ¹⁴C are often useful. For radio-imaging applications, ¹¹C or ¹⁸F are often useful. In some embodiments, the radionuclide is ³H. In some embodiments, the radionuclide is ¹⁴C. In some embodiments, the radionuclide is ¹¹C. And in some embodiments, the radionuclide is ¹⁸F.

Hereinafter all references to compounds of any formula include references to salts, solvates and complexes thereof and to solvates and complexes of salts thereof.

The compounds include a number of formulae as herein defined, including all polymorphs and crystal habits thereof, prodrugs and isomers thereof (including optical, geometric and tautomeric isomers) as hereinafter defined and isotopically-labelled compounds of the invention.

Before purification, the compounds may exist as a mixture of enantiomers depending on the synthetic procedure used. The enantiomers can be separated by conventional techniques known in the art. Thus the compounds cover individual enantiomers as well as mixtures thereof.

For some of the steps of the process of preparation of the compounds of formula (I), it may be necessary to protect potential reactive functions that are not wished to react, and to cleave said protecting groups in consequence. In such a case, any compatible protecting radical can be used. In particular methods of protection and deprotection such as those described by T. W. Greene (Protective Groups in Organic Synthesis, A. Wiley-Interscience Publication, 1981) or by P. J. Kocienski (Protecting groups, Georg Thieme Verlag, 1994), can be used. All of the above reactions and the preparations of novel starting materials used in the preceding methods are conventional and appropriate reagents and reaction conditions for their performance or preparation as well as procedures for isolating the desired products will be well-known to those skilled in the art with reference to literature precedents and the examples and preparations hereto.

Also, the compounds as well as intermediates for the preparation thereof can be purified according to various well-known methods, such as for example crystallization or chromatography.

The method of treatment or the compound for use in the treatment of solid tumours, leukaemia, lymphoma, sarcoma, or carcinoma as defined hereinbefore may be applied as a sole therapy or be a combination therapy with an additional active agent.

The method of treatment or the compound for use in the treatment of solid tumours, leuekaemia, lymphoma, sarcoma, or carcinoma may involve, in addition to the compound of the invention, conventional surgery or radiotherapy or chemotherapy. Such chemotherapy may include one or more of the following categories of anti-cancer agents:

(i) antiproliferative/antineoplastic drugs and combinations thereof, such as alkylating agents (for example cis-platin, oxaliplatin, carboplatin, cyclophosphamide, nitrogen mustard, bendamustin, melphalan, chlorambucil, busulphan, temozolamide and nitrosoureas); antimetabolites (for example gemcitabine and antifolates such as fluoropyrimidines like 5-fluorouracil and tegafur, raltitrexed, methotrexate, pemetrexed, cytosine arabinoside, and hydroxyurea); antibiotics (for example anthracyclines like adriamycin, bleomycin, doxorubicin, daunomycin, epirubicin, idarubicin, mitomycin-C, dactinomycin and mithramycin); antimitotic agents (for example vinca alkaloids like vincristine, vinblastine, vindesine and vinorelbine and taxoids like taxol and taxotere and polokinase inhibitors); proteasome inhibitors, for example carfilzomib and bortezomib; interferon therapy; and topoisomerase inhibitors (for example epipodophyllotoxins like etoposide and teniposide, amsacrine, topotecan, mitoxantrone and camptothecin); (ii) cytostatic agents such as antiestrogens (for example tamoxifen, fulvestrant, toremifene, raloxifene, droloxifene and iodoxyfene), antiandrogens (for example bicalutamide, flutamide, nilutamide and cyproterone acetate), LHRH antagonists or LHRH agonists (for example goserelin, leuprorelin and buserelin), progestogens (for example megestrol acetate), aromatase inhibitors (for example as anastrozole, letrozole, vorazole and exemestane) and inhibitors of 5α-reductase such as finasteride; (iii) anti-invasion agents, for example dasatinib and bosutinib (SKI-606), and metalloproteinase inhibitors, inhibitors of urokinase plasminogen activator receptor function or antibodies to Heparanase; (iv) inhibitors of growth factor function: for example such inhibitors include growth factor antibodies and growth factor receptor antibodies, for example the anti-erbB2 antibody trastuzumab [Herceptin™], the anti-EGFR antibody panitumumab, the anti-erbB1 antibody cetuximab, tyrosine kinase inhibitors, for example inhibitors of the epidermal growth factor family (for example EGFR family tyrosine kinase inhibitors such as gefitinib, erlotinib and 6-acrylamido-N-(3-chloro-4-fluorophenyl)-7-(3-morpholinopropoxy)-quinazolin-4-amine (Cl 1033), erbB2 tyrosine kinase inhibitors such as lapatinib); inhibitors of the hepatocyte growth factor family; inhibitors of the insulin growth factor family; modulators of protein regulators of cell apoptosis (for example Bcl-2 inhibitors); inhibitors of the platelet-derived growth factor family such as imatinib and/or nilotinib (AMN107); inhibitors of serine/threonine kinases (for example Ras/Raf signalling inhibitors such as farnesyl transferase inhibitors, for example sorafenib, tipifarnib and lonafarnib), inhibitors of cell signalling through MEK and/or AKT kinases, c-kit inhibitors, abl kinase inhibitors, PI3 kinase inhibitors, Plt3 kinase inhibitors, CSF-1R kinase inhibitors, IGF receptor, kinase inhibitors; aurora kinase inhibitors and cyclin dependent kinase inhibitors such as CDK2 and/or CDK4 inhibitors; (v) antiangiogenic agents such as those which inhibit the effects of vascular endothelial growth factor, for example the anti-vascular endothelial cell growth factor antibody bevacizumab (Avastin™); thalidomide; lenalidomide; and for example, a VEGF receptor tyrosine kinase inhibitor such as vandetanib, vatalanib, sunitinib, axitinib and pazopanib; (vi) gene therapy approaches, including for example approaches to replace aberrant genes such as aberrant p53 or aberrant BRCA1 or BRCA2; (vii) immunotherapy approaches, including checkpoint inhibitors of targets such as PD-1, PD-L1 and CTCLA-4, for example antibody therapy such as alemtuzumab, rituximab, ibritumomab tiuxetan (Zevalin®), pembrolizumab and ofatumumab; interferons such as interferon α; interleukins such as IL-2 (aldesleukin); interleukin inhibitors for example IRAK4 inhibitors; cancer vaccines including prophylactic and treatment vaccines such as HPV vaccines, for example Gardasil, Cervarix, Oncophage and Sipuleucel-T (Provenge); and toll-like receptor modulators for example TLR-7 or TLR-9 agonists; and (viii) cytotoxic agents for example fludaribine (fludara), cladribine, pentostatin (Nipent™); (ix) steroids such as corticosteroids, including glucocorticoids and mineralocorticoids, for example aclometasone, aclometasone dipropionate, aldosterone, amcinonide, beclomethasone, beclomethasone dipropionate, betamethasone, betamethasone dipropionate, betamethasone sodium phosphate, betamethasone valerate, budesonide, clobetasone, clobetasone butyrate, clobetasol propionate, cloprednol, cortisone, cortisone acetate, cortivazol, deoxycortone, desonide, desoximetasone, dexamethasone, dexamethasone sodium phosphate, dexamethasone isonicotinate, difluorocortolone, fluclorolone, flumethasone, flunisolide, fluocinolone, fluocinolone acetonide, fluocinonide, fluocortin butyl, fluorocortisone, fluorocortolone, fluocortolone caproate, fluocortolone pivalate, fluorometholone, fluprednidene, fluprednidene acetate, flurandrenolone, fluticasone, fluticasone propionate, halcinonide, hydrocortisone, hydrocortisone acetate, hydrocortisone butyrate, hydrocortisone aceponate, hydrocortisone buteprate, hydrocortisone valerate, icomethasone, icomethasone enbutate, meprednisone, methylprednisolone, mometasone paramethasone, mometasone furoate monohydrate, prednicarbate, prednisolone, prednisone, tixocortol, tixocortol pivalate, triamcinolone, triamcinolone acetonide, triamcinolone alcohol and their respective pharmaceutically acceptable derivatives. A combination of steroids may be used, for example a combination of two or more steroids mentioned in this paragraph; (x) targeted therapies, for example PI3Kd inhibitors, for example idelalisib and perifosine.

Such combination treatment may be achieved byway of the simultaneous, sequential or separate dosing of the individual components of the treatment. Such combination products may be administered so that the combination is provided in a therapeutically effective amount, for example the compounds of this invention may be administered within a therapeutically effective dosage range described herein and the other pharmaceutically-active agent may be administered in an amount of less than or within its approved dosage range.

According to a further aspect of the invention there is provided a pharmaceutical product comprising a compound of the first aspect of the invention, or a pharmaceutically acceptable salt thereof as defined herein and an additional active agent. The additional active agent may be a cancer therapy as defined hereinbefore for the combination treatment of cancer.

According to a further aspect of the invention there is provided a method of treating cancer comprising administering a therapeutically effective amount of a compound of the invention, or a pharmaceutically acceptable salt thereof simultaneously, sequentially or separately with an additional anti-cancer agent, as defined hereinbefore, to a patient in need thereof.

According to a further aspect of the invention there is provided a compound of the invention, or a pharmaceutically acceptable salt thereof for use simultaneously, sequentially or separately with an additional anti-cancer agent as defined herein, in the treatment of cancer.

According to another aspect of the invention there is provided a use of the compound of the invention in combination with an anti-cancer agent, such as those hereinbefore described. The compound of formula (I) may be used simultaneously, sequentially or separately with the additional anti-cancer agent. The use may be in a single combination product comprising the compound of the invention and the anti-cancer agent. The additional anti-cancer agent may be a further compound of the first aspect of the invention.

According to a further aspect there is provided a method of providing a combination product, wherein the method comprises providing a compound of the invention simultaneously, sequentially or separately with an anti-cancer agent, as defined hereinbefore. The method may comprise combining the compound of the invention and the anti-cancer agent in a single dosage form. Alternatively the method may comprise providing the anti-cancer agent as separate dosage forms.

Compounds of the invention may exist in a single crystal form or in a mixture of crystal forms or they may be amorphous. Thus, compounds of the invention intended for pharmaceutical use may be administered as crystalline or amorphous products. They may be obtained, for example, as solid plugs, powders, or films by methods such as precipitation, crystallization, freeze drying, or spray drying, or evaporative drying. Microwave or radio frequency drying may be used for this purpose.

For the above-mentioned compounds of the invention the dosage administered will, of course, vary with the compound employed, the mode of administration, the treatment desired and the disorder indicated. For example, if the compound of the invention is administered orally, then the daily dosage of the compound of the invention may be in the range from 0.01 micrograms per kilogram body weight (μg/kg) to 100 milligrams per kilogram body weight (mg/kg).

A compound of the invention, or pharmaceutically acceptable salt thereof, may be used on their own but will generally be administered in the form of a pharmaceutical composition in which the compounds of the invention, or pharmaceutically acceptable salt thereof, is in association with a pharmaceutically acceptable adjuvant, diluent or carrier. Conventional procedures for the selection and preparation of suitable pharmaceutical formulations are described in, for example, “Pharmaceuticals—The Science of Dosage Form Designs”, M. E. Aulton, Churchill Livingstone, 1988.

Depending on the mode of administration of the compounds of the invention, the pharmaceutical composition which is used to administer the compounds of the invention will preferably comprise from 0.05 to 99% w (percent by weight) compounds of the invention, more preferably from 0.05 to 80% w compounds of the invention, still more preferably from 0.10 to 70% w compounds of the invention, and even more preferably from 0.10 to 50% w compounds of the invention, all percentages by weight being based on total composition.

The pharmaceutical compositions may be administered topically (e.g. to the skin) in the form, e.g., of creams, gels, lotions, solutions, suspensions, or systemically, e.g. by oral administration in the form of tablets, capsules, syrups, powders or granules; or by parenteral administration in the form of a sterile solution, suspension or emulsion for injection (including intravenous, subcutaneous, intramuscular, intravascular or infusion); by rectal administration in the form of suppositories; or by inhalation in the form of an aerosol.

For oral administration the compounds of the invention may be admixed with an adjuvant or a carrier, for example, lactose, saccharose, sorbitol, mannitol; a starch, for example, potato starch, corn starch or amylopectin; a cellulose derivative; a binder, for example, gelatine or polyvinylpyrrolidone; and/or a lubricant, for example, magnesium stearate, calcium stearate, polyethylene glycol, a wax, paraffin, and the like, and then compressed into tablets. If coated tablets are required, the cores, prepared as described above, may be coated with a concentrated sugar solution which may contain, for example, gum arabic, gelatine, talcum and titanium dioxide. Alternatively, the tablet may be coated with a suitable polymer dissolved in a readily volatile organic solvent.

For the preparation of soft gelatine capsules, the compounds of the invention may be admixed with, for example, a vegetable oil or polyethylene glycol. Hard gelatine capsules may contain granules of the compound using either the above-mentioned excipients for tablets. Also liquid or semisolid formulations of the compound of the invention may be filled into hard gelatine capsules. Liquid preparations for oral application may be in the form of syrups or suspensions, for example, solutions containing the compound of the invention, the balance being sugar and a mixture of ethanol, water, glycerol and propylene glycol. Optionally such liquid preparations may contain colouring agents, flavouring agents, sweetening agents (such as saccharine), preservative agents and/or carboxymethylcellulose as a thickening agent or other excipients known to those skilled in art.

For intravenous (parenteral) administration the compounds of the invention may be administered as a sterile aqueous or oily solution.

The size of the dose for therapeutic purposes of compounds of the invention will naturally vary according to the nature and severity of the conditions, the age and sex of the animal or patient and the route of administration, according to well-known principles of medicine.

Dosage levels, dose frequency, and treatment durations of compounds of the invention are expected to differ depending on the formulation and clinical indication, age, and co-morbid medical conditions of the patient.

Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Methods for Synthesizing Compounds

Certain ions of the invention can be synthesised according to or analogously to methods described in the General Schemes below and/by other techniques known to those of ordinary skill in the art. Certain ions of the invention can be synthesised according to or analogously to the methods described in the Examples. Certain compounds of formula (I) can be made by Scheme A.

Amide bond formation between N-desmethyl-azithromycin (1) and phosphonium carboxylic acid (2) can deliver phosphonium amide (3). The reaction can be accomplished by standard peptide coupling reagents, such as HATU or TATU or 1,3-dicyclohexylcarboiimide (DCC) in the presence of HOAT, in the presence of a base, such as N,N-diisopropylethylamine (DIEA), in an organic solvent, such as DCM, at a temperature of 25 to 40° C. Phosphonium carboxylic acid (2) can be prepared from reaction of halide (4) (X═C or Br) with phosphine PR^(1a)R^(1b)R^(1c) (7). The reaction can be accomplished by heating in an organic solvent, such as MeCN at a temperature from 50 to 80° C.

Certain compounds of formula (I) can be made by Scheme B.

Reaction of N-desmethyl-azithromycin (1) with halo sulphonic acid (5) (where X═Cl or Br) can furnish halo sulphonamide (6). The reaction can be performed using SOCl₂ in an organic solvent, such as DMF or DCM, at a temperature from 20 to 60° C. Reaction of phosphine (7) with halo sulphonamide (6) can deliver phosphonium sulphonamide (8). The reaction can be accomplished by heating in an organic solvent, such as MeCN at a temperature from 50 to 80° C.

Certain compounds of formula (I) can be made by Scheme C.

Reaction of N-desmethyl-azithromycin (1) with phosphonium chlorocarbonate (9) can furnish phosphonium carbamate (10). The reaction can be accomplished in the presence of a base, such as pyridine, in an organic solvent, such as DCM, at a temperature from 0° C. to room temperature. Phosphonium chloroacetate (9) can be synthesised from phosphonium alcohol (11) through treatment with triphosgene in the presence of a base, such as N,N-diisopropylethylamine (DIEA), in an organic solvent, such as THF, at a temperature from −5 to 5° C. Phosphonium alcohol (11) can be synthesised from halo alcohol (12) (where X═C or Br) and phosphine PR^(1a)R^(1b)R^(1c) (7). The reaction can be accomplished by heating in an organic solvent, such as MeCN, at a temperature from 50 to 80° C.

Certain compounds of formula (I) can be made by Scheme D.

Reductive amination of N-desmethyl-azithromycin (1) with aldehyde (13), can furnish amine (14), where LG represents a leaving group, such as Cl, Br, I, tosyl or mesylate and L_(2a) is one carbon shorter than L₂. The reaction can be accomplished using an appropriate reducing agent, such as NaBH₃CN in the presence of a source of acid, such as CH₃COOH, in an organic solvent, such as DMF, at a temperature of 25 to 80° C. Displacement of the LG in (14) with phosphine (7) can deliver phosphonium amine (15). The reaction can be performed in an organic solvent such as MeCN, at a temperature of 50 to 90° C. As an adaptation addition of a metal iodide, such as NaI or KI in the cases where the LG is not I can facilitate formation of the I in situ as a potentially more effective LG.

Certain compounds of formula (II) can be made by Scheme E.

Removal of the cladinosyl sugar in phosphonium amide (3) to give (16) can be accomplished by the treatment of a mineral acid, such as HCl, in a solvent such as MeOH, at room temperature.

Replacement of amine (1) in Scheme A with amine (17) (prepared as described in WO2011116312) can give phosphonium amide (18).

EXPERIMENTAL

Analytical Methods

NMR spectra were obtained on a 400 MHz Bruker AV III

UPLC/MS was carried out using a Waters Acquity QDa mass detector and Method A, G, J or Waters SQ mass detector and Methods B, C, D, E, F, I or Waters Xevo G2-XS Q-Tof and method H

Method A

Column: Waters Acquity UPLC CSH C18, 1.7 μm, 2.1×30 mm; Gradient Eluent: 5-95% MeCN/H₂O containing 0.1% HCOOH; Time: 0-10 min

Method B

Column: Waters Acquity UPLC CSH C18, 1.7 μm, 2.1×50 mm; Gradient Eluent: 2-98% MeCN/H₂O containing 0.02% HCOOH; Time: 0-4.5 min

Method C

Column: Waters Acquity UPLC CSH C18, 1.7 μm, 2.1×50 mm; Gradient Eluent: 2-98% MeCN containing 0.035% TFA/H₂O containing 0.05% TFA; Time: 0-4.5 min

Method D

Column: Waters Acquity UPLC CSH C18, 1.7 μm, 2.1×100 mm; Gradient Eluent: 2-98% MeCN containing 0.035% TFA/H₂O containing 0.05% TFA; Time: 0-15 min

Method E

Column: Waters Acquity UPLC BEH C18, 1.7 μm, 2.1×30 mm; Gradient Eluent: 5-95% MeCN/H₂O containing 10 mM (NH₄)₂CO₃; Time: 0-3 min

Method F

Column: Waters Acquity UPLC CSH C18, 1.7 μm, 2.1×50 mm; Gradient Eluent: 2-100% MeCN containing 0.035% TFA/H₂O containing 0.05% TFA; Time: 0-3 min

Method G

Column: Waters Acquity UPLC BEH C18, 1.7 μm, 2.1×30 mm; Gradient Eluent: 5-95% MeCN/H₂O containing 10 mM (NH₄)₂CO₃; Time: 0-3 min

Method H

Column: Cortecs UPLC C18, 1.6 μm, 2.1×30 mm; Gradient Eluent: 5-95% MeCN/H₂O containing 0.1% HCOOH; Time: 0-1.1 min

Method I

Column: Waters Acquity UPLC BEH C18, 1.7 μm, 2.1×30 mm; Gradient Eluent: 5-95% MeCN/H₂O containing 10 mM (NH₄)₂CO₃; Time: 0-15 min

Method J

Column: Waters Acquity UPLC CSH C18, 1.7 μm, 2.1×30 mm; Gradient Eluent: 5-95% MeCN/H₂O containing 0.1% HCOOH; Time: 0-3 min

Preparative HPLC was carried out using a ZQ Mass Spectrometer and Method A or Gilson PLC2020 and Method B,C

Method A

Waters X-Select Prep-C18, 5 μm, 19×50 mm eluting with MeCN/H₂O/0.1% HCOOH

Method B

Gemini NX-C18, 10 μm, 30×250 mm eluting with a mixture of MeCN/0.035% TFA and H₂O/0.05% TFA

Method C

Gemini NX-C18, 10 μm, 50×300 mm eluting with a mixture of MeCN/H₂O/0.1% TFA

General protocol for amide coupling (Scheme A)

A1—To a stirred solution of N-desmethyl-azithromycin (1 equivalent), the corresponding phosphonium acid (1.1 equivalents) and HATU (1.2 equivalents) in DCM (10 mL) was added N,N-diisopropylethylamine (DIEA) (2 equivalents). After stirring at room temperature for 16 to 20 h the reaction mixture is concentrated and the resulting residue diluted with 7M NH₃ MeOH and stirred for a further 16 to 20 h. The reaction mixture is then concentrated under reduced pressure and diluted with EtOAc. The organic is washed sequentially with saturated aqueous NaHCO₃, NH₄Cl and brine. The organic is dried over Na₂SO₄ and concentrated under reduced pressure to give the crude product, which is purified by chromatography to give the desired final product

A2—To a stirred solution of N-desmethyl-azithromycin (1 equivalent), the corresponding phosphonium acid (1.1 equivalents) and HATU (1.2 equivalents) in DCM (10 mL) was added N,N-diisopropylethylamine (DIEA) (2 equivalents). After stirring at room temperature for 16 to 20 h the reaction mixture is concentrated under reduced pressure and diluted with EtOAc. The organic is washed with saturated aqueous NaHCO₃, dried over Na₂SO₄ and concentrated under reduced pressure. The resulting residue is diluted with MeOH and the stirring solution heated at 50° C. for 16 to 20 h. On cooling the reaction is concentrated under reduced pressure and diluted with EtOAc. The organic is washed sequentially with saturated aqueous NaHCO₃, NH₄Cl and brine. The organic is dried over Na₂SO₄ and concentrated under reduced pressure to give the crude product, which is purified by chromatography. The organic is dried over Na₂SO₄ and concentrated under reduced pressure to give the crude product, which is purified by chromatography to give the desired final product.

General protocol for reductive amination (Scheme D)

Step 1—To a stirred solution of N-desmethyl-azithromycin (1 equivalent), LG-L_(2a)-CHO (where LG presents a leaving group; L_(2a) is one carbon shorter than L2) (3.5 equivalents) and CH₃COOH (10 equivalents) in DMF (10 mL) is added NaBH₃CN (2 equivalents). The resulting mixture is heated at 75° C. for 90 min to 16 h. On cooling the reaction is quenched with H₂O, saturated aqueous NaHCO₃ and diluted with DCM. The aqueous layer is extracted further with DCM and the combined organics washed with saturated aqueous NaHCO₃ and brine. After drying over Na₂SO₄ the organic is passed through a phase separator and concentrated under reduced pressure to give the crude product, which is purified by chromatography and used in step 2.

Step 2—The resulting purified product from step 1 is dissolved in MeCN (10 mL) and treated with the corresponding phosphine (3 equivalents) and NaI (3 equivalents). After thermal heating at 70 to 85° C. for 16 to 20 h the reaction mixture is cooled to room temperature and concentrated under reduced pressure. The resulting residue is purified by chromatography to give the final desired product. As an adaptation, the reaction can be conducted under microwave conditions at 100° C. for 2 to 6 h.

General protocol for formation of phosphonium carboxylic acids (2)

To a solution of Br-L₂-COOH (1 equivalent) in MeCN (10 mL) is added the corresponding phosphine (3 equivalents). After heating at 60° C. for 16 to 20 h the reaction mixture is cooled to room temperature and concentrated under reduced pressure. The resulting residue is purified by chromatography to give the desired phosphonium carboxylic acid product.

The following abbreviations have been used throughout the specification in the examples and the description: dichloromethane (DCM), tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 4-dimethylaminopyridine (DMAP), N,N,diisopropylethylamine (DIEA), trifluoroacetic acid (TFA), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1-hydroxy-7-azabenzotriazole (HOAT), O-(7-azabenzotriazole-1-yl)N,N,N′,N′-tetramethyluronium tetrafluoroborate (TATU), (1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate) (HATU).

Example 1—{6-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-6-oxohexyl}tris(3,5-dimethylphenyl)phosphoniumhexafluorophosphate(V)

Prepared following amide coupling procedure A2 using (5-carboxypentyl)tris(3,5-dimethylphenyl)phosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method E) 1178 [M]⁺; RT 2.22 min

Example 2—{6-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-6-oxohexyl}diphenyl(3-sulfophenyl)phosphoniumhexafluorophosphate(V)

Prepared following amide coupling procedure A2 using (5-carboxypentyl)diphenyl(3-sulfophenyl)phosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method G) 1174 [M]⁺; RT 1.27 min

Example 3—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}tris(4-fluorophenyl)phosphonium hexafluorophosphate(V)

Prepared following amide coupling procedure A2 using (7-carboxyheptyl)tris(4-fluorophenyl)phosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method E) 1176 [M]⁺; RT 1.95 min

Example 4—tris(4-chlorophenyl)({8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl})phosphoniumhexafluorophosphate(V)

Prepared following amide coupling procedure A2 using (7-carboxyheptyl)tris(4-chlorophenyl)phosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method G) 1225 [M]⁺; RT 1.87 min

Example 5—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}tris(4-methoxyphenyl)phosphoniumhexafluorophosphate(V)

Prepared following amide coupling procedure A1 using (7-carboxyheptyl)tris(4-methoxyphenyl)phosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method G) 1212 [M]⁺; RT 1.77 min

Example 6—[2′,6′-bis(propan-2-yloxy)-[1,1′-biphenyl]-2-yl]dicyclohexyl{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}phosphonium hexafluorophosphate(V)

Prepared following amide coupling procedure A1 using (7-carboxyheptyl)dicyclohexyl[2′,6′-diisopropoxy-[1,1′-biphenyl]-2-yl)phosphonium bromide.

Title compound isolated as a white solid.

LC-MS (Method H) 1327 [M]⁺; RT 0.9 min

Example 7—tricyclohexyl({8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl})phosphonium hexafluorophosphate(V)

Prepared following amide coupling procedure A1 using (7-carboxyheptyl)tricyclohexylphosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method 1) 1140 [M]⁺; RT 8.24 min

Example 8—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}diphenyl(pyridine-2-yl)phosphonium hexafluorophosphate(V)

Prepared following amide coupling procedure A1 using (7-carboxyheptyl)diphenyl(pyridin-2-yl)phosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method G) 1123 [M]⁺; RT 1.65 min

Example 9—tricyclohexyl({6-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]hexyl})phosphonium iodide

Prepared following the general reductive amination procedure using 6-chlorohexanal in step 1 and tricyclohexylphosphine in step 2 under thermal heating conditions. Title compound isolated as a white solid.

LC-MS (Method H) 1098 [M]⁺; RT 0.77 min

Example 10—dicyclohexyl({6-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]hexyl})[2′-(dimethylamino)-[1,1′-biphenyl]-2-yl]phosphonium iodide

Prepared following the general reductive amination procedure using 6-chlorohexanal in step 1 and 2′-(dicyclohexylphosphanyl)-N, N-dimethyl-[1,1′-biphenyl]-2-amine in step 2 under microwave heating conditions. Title compound isolated as a white solid.

1H NMR (Method A) (DMSO-d₆): δ (delta) ppm 8.05 (dd, 1H), 7.88 (t, J=7.6 Hz, 1H), 7.72 (t, J=7.7 Hz, 1H), 7.52 (ddd, 1H), 7.50-7.43 (m, 1H), 7.24-7.17 (m, 1H), 7.17-7.11 (m, 1H), 4.94-4.85 (m, 1H), 4.80 (d, J=4.8 Hz, 1H), 4.44 (d, J=7.2 Hz, 1H), 4.37 (d, J=2.8 Hz, 1H), 4.27 (d, J=7.4 Hz, 1H), 4.13-4.04 (m, 2H), 4.04-3.97 (m, 1H), 3.97-3.87 (m, 1H), 3.76-3.64 (m, 1H), 3.57-3.46 (m, 2H), 3.23 (s, 3H), 3.17 (d, J=5.3 Hz, 1H), 3.11-3.01 (m, 1H), 2.92 (t, J=8.4 Hz, 1H), 2.87-2.76 (m, 2H), 2.76-2.65 (m, 2H), 2.64-2.46 (m, 3H), 2.39 (s, 7H), 2.35-2.02 (m, 8H), 2.02-1.56 (m, 15H), 1.56-1.34 (m, 8H), 1.33-0.93 (m, 41H), 0.87 (d, J=6.6 Hz, 3H), 0.80 (t, J=7.4 Hz, 3H); 31P NMR (162 MHz, DMSO-d₆): δ ppm +35.51 (s); LC-MS (Method H) 1210.9 [M]⁺; RT 0.8 min

Example 11—{8-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]octyl}({2-[(dimethylamino)methyl]phenyl})diphenylphosphonium iodide

Prepared following the general reductive amination procedure using 8-chlorooctanal in step 1 and {[2-(diphenylphosphanyl)phenyl]methyl}dimethylamine in step 2 under thermal heating conditions. Title compound isolated as a white solid.

LC-MS (Method 1) 1165 [M]P: RT 9.27 min

Example 12—{8-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]octyl}[4-(dimethylamino)phenyl]diphenylphosphonium iodide

Prepared following the general reductive amination procedure using 8-chlorooctanal in step 1 and 4-(diphenylphosphanyl)-N,N-dimethylaniline in step 2 under thermal heating conditions. Title compound isolated as a white solid.

LC-MS (Method 1) 1151 [M]⁺; RT 8.96 min

Example 13—{8-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]octyl}tris(4-methoxyphenyl)phosphonium iodide

Prepared following the general reductive amination procedure using 8-chlorooctanal in step 1 and tris(4-methoxyphenyl)phosphine in step 2 under thermal heating conditions.

Title compound isolated as a white solid.

LC-MS (Method 1) 1198 [M]⁺; RT 8.58 min

Example 14—{[1,1′-biphenyl]-2-yl}({8-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]octyl})diphenyl)phosphonium iodide

Prepared following the general reductive amination procedure using 8-chlorooctanal in step 1 and [1,1′-biphenyl]-2-yldiphenylphosphine in step 2 under thermal heating conditions. Title compound isolated as a white solid.

LC-MS (Method 1) 1184 [M]⁺; RT 9.52 min

Example 15—{10-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]decyl}tris(4-methoxyphenyl)phosphonium iodide

Prepared following the general reductive amination procedure using 10-chlorodecanal in step 1 and tris(4-methoxyphenyl)phosphine in step 2 under thermal heating conditions.

Title compound isolated as a white solid.

LC-MS (Method 1) 1226 [M]⁺; RT 9.75 min

Example 16—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}tris(3,5-dimethylphenyl)phosphonium hexafluorophosphate(V)

Prepared following amide coupling procedure A2 using (7-carboxyheptyl)tris(3,5-dimethylphenyl)phosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method 1) 1206 [M]⁺; RT 9.12 min

Example 17—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}({2-[(dimethylamino)methyl]phenyl})diphenylphosphonium hexafluorophosphate(V)

Prepared following amide coupling procedure A2 using (7-carboxyheptyl)({2-[(dimethylamino)methyl]phenyl})diphenylphosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method 1) 1179 [M]⁺: RT 7.62 min

Example 18—{[1,1′-biphenyl]-2-yl}({8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl})diphenylphosphonium hexafluorophosphate(V)

Prepared following amide coupling procedure A2 using {[1,1′-biphenyl]-2-yl}(7-carboxyheptyl)diphenylphosphonium bromide. Title compound isolated as a white solid.

LC-MS (Method 1) 1198 [M]⁺; RT 7.79 min

Example 19—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}[4-(dimethylamino)phenyl]diphenylphosphonium hexafluorophosphate(V)

Prepared following amide coupling procedure A2 using (7-carboxyheptyl)[4-(dimethylamino)phenyl]diphenylphosphonium bromide. Title compound isolated as a white solid. LC-MS (Method 1) 1165 [M]⁺; RT 7.60 min

Example 20—{8-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10,13-tetrahydroxy-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]octyl}tris(4-methoxyphenyl)phosphonium iodide

A solution of {8-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]octyl}tris(4-methoxyphenyl)phosphonium iodide (prepared as described in Example 13) (65 mg, 0.05 mmol) in MeOH (13 mL) was treated with 10 M HCl in MeOH (0.4 mL). The resulting reaction mixture was stirred at room temperature for 16 h and then neutralised with saturated aqueous NaHCO₃. The mixture was concentrated under reduced pressure and diluted with DCM. The DCM was separated and washed with 2 M HCl. The combined aqueous acidic fractions were basified to pH 10 with 2 M NaOH and extracted with DCM (3×15 mL). The combined organics from the basic extraction were dried over Na₂SO₄ and concentrated under reduced pressure. The resulting residue was purified by column chromatography eluting with 0-10% MeOH/0.7 M NH₃ in DCM to give the title compound as a glass.

LC-MS (Method 1) 1140 [M]⁺: RT 7.70 min

Example 21—{8-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10,13-tetrahydroxy-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]octyl}[4-(dimethylamino)phenyl]diphenylphosphonium iodide

Prepared following the procedure of Example 20 using {8-(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]octyl}[4-(dimethylamino)phenyl]diphenylphosphonium iodide (prepared as described in Example 12). Title compound isolated as a glass.

LC-MS (Method I) 993 [M]⁺; RT 7.89 min

Example 22—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}(methyl)diphenylphosphonium chloride (11-carboxyundecyl)(methyl)diphenylphosphonium bromide

A suspension of 12-bromododecanoic acid (1.33 g, 4.76 mmol) in MeCN (20 mL) was warmed to 40° C. until a clear solution was obtained. The resulting solution was degassed with bubbling N₂ for 30 min and treated with methyldiphenylphosphine (0.93 mL, 4.99 mmol). The resulting solution was heated at 90° C. under N₂ for 16 h. On cooling to room temperature the solution was added to MTBE (100 mL) and (11-carboxyundecyl)(methyl)diphenylphosphonium bromide (2.1 g) collected as a colourless gum, which was used in the next step without further purification.

LC-MS (Method J) 399.4 [M]⁺; RT 1.08 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecy}(methyl)diphenylphosphonium chloride

To a solution of (11-carboxyundecyl)(methyl)diphenylphosphonium bromide (prepared as described in Example 22 step (a)) (0.16 g, 0.33 mmol), 1-hydroxy-7-azabenzotriazole (HOAt) (44 mg, 0.32 mmol), N,N′-diisopropylcarbodiimide (DIC) (51 μL, 0.33 mmol) and N,N-diisopropylethylamine (DIEA) (143 μL, 0.82 mmol) in DCM (5 mL) was added N-desmethyl-azithromycin (0.32 g, 0.40 mmol). The resulting solution was heated at 40° C. After 16 h the reaction was recharged with further (11-carboxyundecyl)(methyl)diphenylphosphonium bromide (0.16 g, 0.33 mmol), 1-hydroxy-7-azabenzotriazole (HOAt) (44 mg, 0.32 mmol), N,N′-diisopropylcarbodiimide (DIC) (51 μL, 0.33 mmol) and N,N-diisopropylethylamine (DIEA) (143 μL, 0.82 mmol) and heating continued for a further 16 h. On cooling H₂O (5 mL) was added to the reaction mixture, which was then filtered through a phase separator. The collected organic phase was evaporated under reduced pressure and the resulting residue treated with MeOH (5 mL) at 60° C. for 4 h. On cooling the solvent was concentrated under reduced pressure and the resulting residue taken up in DCM (5 mL) and treated with H₂O (5 mL). The resulting mixture was filtered through a phase separator and the collected organic phase evaporated under reduced pressure. The resulting residue was purified by chromatography eluting with 0-20% MeOH/0.7 M NH₃ in DCM to give a white solid, which was taken up in MeOH (2 mL) and filtered through an Amberlite IRA-400 chloride ion exchange resin. The collected MeOH was recycled through the column 3 x. followed by a fresh volume of MeOH. The combined MeOH washings were concentrated under reduced pressure to give the title compound (32 mg) as a white solid.

LC-MS (Method E) 1116 [M]⁺; RT 2.18 min

Example 23—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}dimethylphenylphosphonium chloride (11-carboxyundecyl)dimethylphenylphosphonium bromide

Prepared following the procedure in Example 22 step (a) using dimethylphenylphosphine. The (11-carboxyundecyl)dimethylphenylphosphonium bromide was collected as a white solid and used in the next step without any further purification.

LC-MS (Method J) 337.4 [M]⁺; RT 0.96 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}dimethylphenylphosphonium chloride

Prepared following the procedure in Example 22 step (b) using (11-carboxyundecyl)dimethylphenylphosphonium bromide (prepared as described in Example 23 step (a)). Title compound isolated as a white solid.

LC-MS (Method E) 1054 [M]⁺; RT 1.94 min

Example 24—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}trimethylphosphonium chloride (11-carboxyundecyl)trimethylphosphonium bromide

Prepared following the procedure in Example 22 step (a) using triimethylphosphine (1 M in toluene). The (11-carboxyundecyl)trimethylphosphonium bromide was collected as a white solid and used in the next step without any further purification.

LC-MS (Method J) 275.3 [M]⁺; RT 0.82 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecy}trimethylphosphonium chloride

Prepared following the procedure in Example 22 step (b) using (11-carboxyundecyl)timethylphosphonium bromide (prepared as described in Example 24 step (a)). Title compound isolated as a white solid.

LC-MS (Method E) 992 [M]+; RT 1.57 min

Example 25—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}trimethylphosphonium chloride (7-carboxyheptyl)trimethylphosphonium bromide

Prepared following the procedure in Example 22 step (a) using triimethylphosphine (1 M in toluene) and 8-bromooctanoic acid. The (7-carboxyheptyl)trimethylphosphonium bromide was collected as a white solid and used in the next step without any further purification.

LC-MS (Method J) 219 [M]⁺; RT 0.18 min

{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}trimethylphosphonium chloride

To a solution of (7-carboxyheptyl)trimethylphosphonium bromide (prepared as described in Example 25 step (a)) (0.32 g, 1.06 mmol), 1-hydroxy-7-azabenzotriazole (HOAt) (0.21 g, 1.38 mmol) and N-desmethyl-azithromycin (0.70 g, 0.96 mmol) in DCM (10 mL) was added N,N′-diisopropylcarbodiimide (DIC) (215 μL, 1.38 mmol) The resulting solution was heated at 35° C. After 16 h solvent was removed under reduced pressure and the resulting residue treated with MeOH (20 mL) at 55° C. for 16 h. On cooling the solvent was removed under reduced pressure and the residue purified by silica column chromatography eluting with 0-20% MeOH/0.7 M NH₃ in DCM to give a white solid, which was taken up in MeOH (10 mL) and filtered through an Amberlite IRA-400 chloride ion exchange resin. The collected MeOH was recycled through the column 3 x. followed by a fresh volume of MeOH. The combined MeOH washings were concentrated under reduced pressure to give the title compound (64 mg) as a white solid.

LC-MS (Method I) 936 [M]⁺; RT 4.93 min

Example 26—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}(methyl)diphenylphosphonium chloride (7-carboxyheptyl)(methyl)diphenylphosphonium bromide

Prepared following the procedure in Example 22 step (a) using 8-bromooctanoic acid. The (7-carboxyheptyl)(methyl)diphenylphosphonium bromide was collected as a white solid and used in the next step without any further purification.

LC-MS (Method J) 343 [M]⁺; RT 0.80 min

{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}(methyl)diphenylphosphonium chloride

Prepared following the procedure in Example 25 step (b) using (7-carboxyheptyl)(methyl)diphenylphosphonium bromide (prepared as described in Example 26 step (a)). Title compound isolated as a white solid.

LC-MS (Method 1) 1060 [M]⁺; RT 5.90 min

Example 27—{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium chloride 4-(diphenylphosphonyl)-1-methyl-1H-pyrazole

Butyllithium (2.5 M in hexanes) (2.73 mL, 6.83 mmol) was added dropwise to a solution of 4-bromo-1-methyl-1H-pyrazole (0.64 mL, 6.21 mmol) in toluene (10 mL) at −78° C. The resulting reaction mixture was allowed to warm to 0° C. After stirring for 15 min chlorodiphenylphosphine (1.27 mL, 6.83 mmol) was added dropwise and the reaction mixture allowed to warm to room temperature. After stirring for 1 h the reaction mixture was diluted with EtOAc (10 mL) and washed with H₂O (10 mL) followed by brine (10 mL). The resulting organics were dried over MgSO₄ and solvent removed under vacuo. The resulting residue was purified by chromatography eluting with 0-50% TBME in isohexane to give 4-(diphenylphosphonyl)-1-methyl-1H-pyrazole (0.78 g) as a colourless oil, which was used in the next step.

LC-MS (Method J) 267 [M+H]⁺; RT 1.56 min

(7-carboxyheptyl)(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium bromide

A solution of 8-bromodoctanoic acid (0.37 g, 1.67 mmol) and 4-(diphenylphosphonyl)-1-methyl-1H-pyrazole (prepared as described in Example 27 step (a)) (0.37 g, 1.39 mmol) in MeCN (3 mL) was degassed with bubbling N₂ for 15 min and then heated at 80° C. under N₂ for 24 h. On cooling to room temperature, the solvent was removed under reduced pressure and the resulting residue purified by silica column chromatography eluting with 0-10% MeOH in DCM to give (7-carboxyheptyl)(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium bromide (0.52 g) as a colourless gum, which was used in the next step. LC-MS (Method J) 409 [M]⁺; RT 0.85 min

{8-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-8-oxooctyl}(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium chloride

Prepared following the procedure in Example 25 step (b) using (7-carboxyheptyl)(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium bromide (prepared as described in Example 27 step (b)). Title compound isolated as a white solid.

LC-MS (Method 1) 1126 [M]⁺; RT 6.02 min

Example 28—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium chloride (11-carboxyundecyl)(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium bromide

Prepared following the procedure in Example 27 step (b) but using 12-bromododecanoic acid. Purification was by silica column chromatography eluting with 0-10% MeOH in DCM. The (11-carboxyundecyl)(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium_bromide_was isolated as a colourless gum and used in the next step.

LC-MS (Method J) 465 [M]⁺; RT 1.13 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecy}(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium chloride

Prepared following the procedure in Example 25 step (b) using (11-carboxyundecyl)(1-methyl-1H-pyrazol-4-yl)diphenylphosphonium_bromide (prepared as described in Example 28 step (a)). Title compound isolated as a white solid.

LC-MS (Method 1) 1182 [M]P: RT 7.20 min

Example 29—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}tris(3,5-dimethylphenyl)phosphonium chloride (11-carboxyundecyl)tris(3,5-dimethylphenyl)phosphonium iodide

A suspension of 12-bromododecanoic acid (0.48 g, 1.72 mmol), tris(3,5-dimethylphenyl)phosphine (0.60 g, 1.73 mmol) and NaI (0.26 g, 1.74 mmol) in MeCN (20 mL) was degassed with bubbling N₂ for 15 min and then heated at 80° C. under N₂ for 16 h. On cooling to room temperature, the solution was filtered, and the solvent removed under reduced pressure. The resulting residue was purified by silica column chromatography eluting with 0-10% MeOH in DCM to give (11-carboxyundecyl)tris(3,5-dimethylphenyl)phosphonium iodide (1.13 q) as a yellow gum, which was used in the next step.

LC-MS (Method J) 545 [M]⁺; RT 1.51 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecy}tris(3,5-dimethylphenyl)phosphonium chloride

Prepared following the procedure in Example 22 step (b) using (11-carboxyundecyl)tris(3,5-dimethylphenyl)phosphonium iodide (prepared as described in Example 29 step (a)). Title compound isolated as a white solid.

LC-MS (Method 1) 1262 [M]⁺; RT 11.47 min

Example 30—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}tris(3-methylphenyl)phosphonium chloride (11-carboxyundecyl)tris(3-methylphenyl)phosphonium iodide

Prepared following the procedure in Example 29 step (a) using tris(3-methylphenyl)phosphine. The (11-carboxyundecyl)tris(3-methylphenyl)phosphonium iodide was isolated as a yellow gum, which was used in the next step.

LC-MS (Method J) 503 [M]P: RT 3 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecy}tris(3-methylphenyl)phosphonium chloride

Prepared following the procedure in Example 22 step (b) using (11-carboxyundecyl)tris(3-methylphenyl)phosphonium iodide_(prepared as described in Example 30 step (a)). Title compound isolated as a white solid.

LC-MS (Method 1) 1220 [M]⁺; RT 10.67 min

Example 31—tricyclohexyl({12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl})phosphonium chloride (11-carboxyundecyl)tricyclohexylphosphonium iodide

Prepared following the procedure in Example 29 step (a) using tricyclohexylphosphine. The (11-carboxyundecyl)tricyclohexylphosphonium iodide was isolated as a colourless gum, which was used in the next step.

LC-MS (Method J) 479 [M]⁺; RT 1.40 min

tricyclohexyl({12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecy})phosphonium chloride

Prepared following the procedure in Example 22 step (b) using (11-carboxyundecyl)tricyclohexylphosphonium iodide (prepared as described in Example 31 step (a)). Title compound isolated as a white solid.

LC-MS (Method 1) 1196 [M]⁺; RT 10.43 min

Example 32—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}(oxetan-3-yl)diphenylphosphonium chloride (oxetan-3-yl)diphenylphosphine

A stirred solution of diphenylphosphine (2.3 mL, 13.22 mmol) in dry THE (5 mL) at 0° C. was treated with n-butyllithium (2.5 M in hexanes) (8.4 mL, 13.4 mmol). After 5 min a solution of 3-bromooxetane (1.7 mL, 20.49 mmol) in dry THE (1 mL) was added dropwise. The reaction mixture was allowed to warm to room temperature. After 16 h the reaction mixture was partitioned between EtOAc (20 mL) and H₂O (20 mL). The aqueous phase was separated and further extracted with EtOAc (20 mL). The combined organic extracts were washed with brine (20 mL) and dried over MgSO₄. The solvent was removed under reduced pressure and the resulting residue was purified by silica column chromatography eluting with 0-10% EtOAc in isohexane to give (oxetan-3-yl)diphenylphosphine (1.14 g) as a white solid, which was used in the next step.

LC-MS (Method J) 243 [M+H]⁺; RT 1.53 min

(11-carboxyundecyl)(oxetan-3-yl)diphenylphosphonium iodide

A suspension of 12-bromododecanoic acid (1.31 g, 4.71 mmol), (oxetan-3-yl)diphenylphosphine (prepared as described in Example 32 step (a)) (1.14 g, 4.71 mmol) and NaI (0.71 g, 4.71 mmol) in MeCN (20 mL) was degassed with bubbling N₂ for 15 min and then heated at 80° C. under N₂ for 16 h. On cooling to room temperature, the solution was added to stirring MTBE (500 mL). After 1 h the resulting gum was isolated by decantation of excess MTBE and taken up in DCM, which was removed under reduced pressure to give (11-carboxyundecyl)(oxetan-3-yl)diphenylphosphonium iodide (1.64 g) as a colourless gum, which was used in the next step without any further purification.

LC-MS (Method J) 441 [M]⁺; RT 1.06 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecy}(oxetan-3-yl)diphenylphosphonium chloride

Prepared following the procedure in Example 22 step (b) using (11-carboxyundecyl)(oxetan-3-yl)diphenylphosphonium iodide (prepared as described in Example 32 step (b)). Title compound isolated as a white solid.

LC-MS (Method 1) 1158 [M]⁺; RT 7.64 min

Example 33—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}diphenyl(propan-2-yl)phosphonium chloride (11-carboxyundecyl)diphenyl(propan-2-yl)phosphonium bromide

Prepared following the procedure in Example 22 step (a) using isopropyldiphenylphosphine. The (11-carboxyundecyl)diphenyl(propan-2-yl)phosphonium bromide was isolated as a colourless gum, which was used in the next step without further purification.

LC-MS (Method J) 427 [M]⁺; RT 1.15 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}diphenyl(propan-2-yl)phosphonium chloride

Prepared following the procedure in Example 22 step (b) using (11-carboxyundecyl)diphenyl(propan-2-yl)phosphonium bromide (prepared as described in Example 33 step (a)). Title compound isolated as a white solid.

LC-MS (Method 1) 1144 [M]P: RT 8.49 min

Example 34—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}(2-methoxyethyl)diphenylphosphonium chloride (11-carboxyundecyl)(2-methoxyethyl)diphenylphosphonium bromide

Prepared following the procedure in Example 27 step (b) but using (2-methoxyethyl)diphenylphosphine. Purification was 0-10% MeOH/7 M NH₃ in DCM. The (11-carboxyundecyl)(2-methoxyethyl)diphenylphosphonium bromide__was isolated as a colourless gum and used in the next step.

LC-MS (Method G) 443 [M]⁺; RT 1.09 min

{12-[(2R,3S,4R,5R,8R,10R,11, R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecy}(2-methoxyethyl)diphenylphosphonium chloride

Prepared following the procedure in Example 25 step (b) using (11-carboxyundecyl)(2-methoxyethyl)diphenylphosphonium bromide (prepared as described in Example 34 step (a)). Title compound isolated as a white solid.

LC-MS (Method 1) 1160 [M]⁺; RT 8.60 min

Example 35—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}(oxan-4-yl)diphenylphosphonium chloride (oxan-4-yl)diphenylphosphine

Prepared following the procedure in Example 32 step (a) using 4-bromotetrahydro-2H-pyran. Purification was by silica column chromatography eluting with 0-30% EtOAc in isohexane. The (oxan-4-yl)diphenylphosphine_was isolated as a colourless oil and used in the next step.

LC-MS (Method G) 271 [M+H]⁺; RT 1.67 min

(11-carboxyundecyl)(oxan-4-yl)diphenylphosphonium iodide

A suspension of 12-bromododecanoic acid (0.59 g, 2.11 mmol), (oxan-4-yl)diphenylphosphine (prepared as described in Example 35 step (a)) (0.6 g, 2.22 mmol) and NaI (0.32 g, 2.11 mmol) in MeCN (10 mL) was degassed with bubbling N₂ for 15 min and then heated in the microwave (Biotage) at 110° C. After 6 h the solvent was removed under reduced pressure and the resulting residue purified by silica column chromatography eluting with 0-20% MeOH/7 M NH₃ in DCM to give (11-carboxyundecyl)(oxan-4-yl)diphenylphosphonium iodide (0.47 g) as a white solid, which was used in the next step.

LC-MS (Method G) 469 [M]⁺; RT 1.06 min

{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}(oxan-4-yl)diphenylphosphonium chloride

Prepared following the procedure in Example 25 step (b) using (11-carboxyundecyl)(oxan-4-yl)diphenylphosphonium iodide (prepared as described in Example 35 step (b)). Title compound isolated as a white solid.

LC-MS (Method 1) 1186 [M]⁺; RT 8.54 min

Example 36—(2S,3R,4S,6R)-4-(dimethylamino)-2-{[(2R,3R,4R,5R,8R,10R,11R,12S,13S,14R)-2-ethyl-3,10-dihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,6,8,10,12,14-heptamethyl-4-({[10-(methyldiphenylphosphoniumyl)decyl]carbamoyl}oxy)-15-oxo-1-oxa-6-azacyclopentadecan-11-yl]oxy}-6-methyloxan-3-yl acetate bromide [10-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)decyl](methyl)diphenylphosphonium bromide

A mixture of 2-(10-bromodecyl)isoindoline-1,3-dione (1.35 g, 3.69 mmol) and methyldiphenylphosphine (0.75 mL, 4.05 mmol) in MeCN (13.5 mL) was heated at 70° C. for 15 h. On cooling the solvent was removed in vacuo and the resulting residue purified by silica column chromatography eluting with 0-10% MeOH in DCM to give [10-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)decyl](methyl)diphenylphosphonium bromide (2 g) as a colourless oil, which was used in the next step.

LC-MS (Method J) 486 [M]+; RT 1.57 min

(10-aminodecyl)(methyl)diphenylphosphonium bromide

To a solution of [10-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)decyl](methyl)diphenylphosphonium bromide (prepared as described in Example 36 step (a))_(2 g, 3.53 mmol) in EtOH (27.2 mL) was added 1 M hydrazine in EtOH (8.83 mL, 8.83 mmol). The resulting reaction mixture was refluxed. After 18 h further quantities of 1 M hydrazine in EtOH (11 mL) was added and refluxing continued for 30 h. On cooling the solvent was removed under vacuo and the resulting residue purified by silica column chromatography eluting with 0-100% EtOAc in DCM followed by 0-20% MeOH in DCM to give (10-aminodecyl)(methyl)diphenylphosphonium bromide (0.58 g) as a white gum, which was used in the next step

LC-MS (Method G) 356 [M]+; RT 1.35 min

(2S,3R,4S,6R)-4-(dimethylamino)-2-{[(2R,3R,4R,5R,8R,10R,11, R,12S,13S,14R)-2-ethyl-3,10-dihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,6,8,10,12,14-heptamethyl-4-({[10-(methyldiphenylphosphoniumyl)decyl]carbamoyl}oxy)-15-oxo-1-oxa-6-azacyclopentadecan-11-yl]oxy}-6-methyloxan-3-yl acetate bromide

A stirred solution of (2S,3S,4R,6R)-6-{[(3aR,4R,7R,8S,9S,10R,11R,13R,16R,16aR)-10-{[(2S,3R,4S,6R)-3-(acetyloxy)-4-(dimethylamino)-6-methyloxan-2-yl]oxy}-4-ethyl-11-hydroxy-3a,7,9,11,13,15,16-heptamethyl-2,6-dioxo-tetradecahydro-2H-[1,3]dioxolo[4,5-c]1-oxa-6-azacyclopentadecan-8-yl]oxy}-4-methoxy-2,4-dimethyloxan-3-yl 1H imidazole-1-carboxylate (prepared as described in European Journal of Medicinal Chemistry 40, 2011, 5196) (2.0 g, 2.19 mmol) in THE (180 mL) was treated with 0.1 M NaOH (37.3 mL, 3.73 mmol) at 0 to 5° C. The reaction mixture was then allowed to warm to room temperature. After stirring for a further 3 h the reaction was diluted with saturated aqueous NH₄C (100 mL) and extracted with EtOAc (3×150 mL). The combined organics were concentrated under reduced pressure and the resulting residue purified by silica column chromatography eluting with 0-10% MeOH/0.7 M NH₃ in DCM to give a white solid (1.32 g) which was used in the next step.

A stirred solution of the white solid (0.27 g) and 10-aminodecyl)(methyl)diphenylphosphonium bromide (prepared as described in Example 36 step (b)) (0.53 g, 0.97 mmol) in pyridine (1 mL) was treated with DBU (0.15 mL, 0.97 mmol) and pyridine hydrochloride (56 mg, 0.49 mmol). After stirring for 15 h the reaction mixture was diluted with DCM (25 mL) and washed with saturated aqueous NaBr (20 mL). The organics were dried through a phase separator and solvent removed under reduced pressure. The resulting residue was purified by silica column chromatography eluting initially with DCM followed by a solvent mixture of DCM/MeOH/NH₃ (90/10/1) to give the title compound as a white solid (42 mg).

LC-MS (Method 1) 1173 [M]⁺; RT 9.10 min

Example 37—(2R,3R,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,10-dihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,6,8,10,12,14-heptamethyl-15-oxo-1-oxa-6-azacyclopentadecan-4-yl N-[10-(methyldiphenylphosphoniumyl)decyl]carbamate bromide

A stirred solution of (2S,3R,4S,6R)-4-(dimethylamino)-2-{[(2R,3R,4R,5R,8R,10R,11R,12S,13S,14R)-2-ethyl-3,10-dihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,6,8,10,12,14-heptamethyl-4-({[10-(methyldiphenylphosphoniumyl)decyl]carbamoyl}oxy)-15-oxo-1-oxa-6-azacyclopentadecan-11-yl]oxy}-6-methyloxan-3-yl acetate bromide_(prepared as described in Example 36) (41.8 mg) in MeOH (0.47 mL) was heated at 45° C. for 15 h. On cooling the solvent was removed under reduced pressure and the resulting residue purified by silica column chromatography eluting initially with DCM followed by a solvent mixture of DCM/MeOH/NH₃ (90/10/1) to give the title compound (19 mg) as a white solid.

LC-MS (Method 1) 1131 [M]⁺; RT 8.60 min

Example 38—(2S,3R,4S,6R)-2-{[(2R,3R,4R,5R,8R,10R,11R,12S,13S,14R)-4-[({10-[dimethyl(phenyl)phosphoniumyl]decyl}carbamoyl)oxy]-2-ethyl-3,10-dihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,6,8,10,12,14-heptamethyl-15-oxo-1-oxa-6-azacyclopentadecan-11-yl]oxy}-4-(dimethylamino)-6-methyloxan-3-yl acetate bromide (10-aminodecyl)dimethylphenylphosphonium bromide

Prepared following the procedure in Example 36 steps (a) and (b) using dimethylphenylphosphine in step (a). Purification was by silica column chromatography eluting initially with EtOAc followed by 0-60% MeOH in DCM. The resulting yellow oil was used in the next step.

LC-MS (Method G) 294 [M]⁺; RT 0.74 min

(2S,3R,4S,6R)-2-{[(2R,3R,4R,5R,8R,10R,11R,12S,13S,14R)-4-[({10-[dimethyl(phenyl)phosphoniumyl]decyl}carbamoyl)oxy]-2-ethyl-3,10-dihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,6,8,10,12,14-heptamethyl-15-oxo-1-oxa-6-azacyclopentadecan-11-yl]oxy}-4-(dimethylamino)-6-methyloxan-3-yl acetate bromide

Prepared following the procedure of Example 36 (step (c)) using (10-aminodecyl)dimethylphenylphosphonium bromide (prepared as described in Example 38 step (a)). The title compound was isolated as a white foam.

LC-MS (Method 1) 1111 [M]P: RT 8.39 min

Example 39—5-{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}-5-phenyl-5H-benzo[b]phosphindol-5-ium chloride 5-(11-carboxyundecyl)-5-phenyl-5H-benzo[b]phosphindol-5-ium bromide

Prepared following the procedure in Example 29 step (a) using 5-phenyl-5H-benzo[b]phosphindole. Purification was by silica column chromatography eluting with 0-10% MeOH in DCM. The resulting yellow oil was used in the next step.

LC-MS (Method J) 459 [M]⁺; RT 2.97 min

5-{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}-5-phenyl-5H-benzo[b]phosphindol-5-ium chloride

Prepared following the procedure in Example 22 step (b) using 5-(11-carboxyundecyl)-5-phenyl-5H-benzo[b]phosphindol-5-ium bromide (prepared as described in Example 39 step (a)). Title compound isolated as a white solid.

LC-MS (Method 1) 1176 [M]⁺; RT 9.71 min

Example 40—(4,4-difluorocyclohexyl)({12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl})diphenylphosphonium chloride (4,4-difluorocyclohexyl)diphenylphosphine

A stirred solution of diphenylphosphine (0.6 mL, 3.45 mmol) in dry degassed THE (5.9 mL) at 0° C. was treated with n-butyllithium (2.5 M in hexanes) (1.4 mL, 3.61 mmol). After 5 min a solution of 4,4-difluorocyclohexyl methanesulphonate (0.74 g, 3.45 mmol) in dry THE (1 mL) was added dropwise. The reaction mixture was allowed to warm to room temperature. After 30 min dry degassed MeOH (0.42 mL) was added and the solvent removed under reduced pressure. The resulting residue was purified by silica column chromatography eluting with 0-10% EtOAc in isohexane to give (4,4-difluorocyclohexyl)diphenylphosphine (0.44 g) as a white solid, which was used in the next step.

LC-MS (Method J) 305 [M+H]⁺; RT 1.89 min

(11-carboxyundecyl)(4,4-difluorocyclohexyl)diphenylphosphonium iodide

Prepared following the procedure in Example 29 step (a) using 4,4-difluorocyclohexyl)diphenylphosphine (prepared as described in Example 40 step (a). Purification was by silica column chromatography eluting with 0-10% MeOH in DCM. The resulting white foam was used in the next step.

LC-MS (Method B) 503 [M]⁺; RT 0.48 min

(4,4-difluorocyclohexyl)({12-[(2R,3S,4R,5R,8R,10R,11, R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl})diphenylphosphonium chloride

Prepared following the procedure in Example 25 step (b) using (11-carboxyundecyl)(4,4-difluorocyclohexyl)diphenylphosphonium iodide (prepared as described in Example 40 step (b)). Title compound isolated as a white solid.

LC-MS (Method 1) 1220 [M]P: RT 9.80 min

Example 41—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10,13-tetrahydroxy-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}(oxetan-3-yl)diphenylphosphonium chloride

A solution of {12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}(oxetan-3-yl)diphenylphosphonium chloride (prepared as described in Example 32) (0.1 g, 0.08 mmol) in MeOH (1 mL) was treated with concentrated HCl (0.1 mL). The resulting reaction mixture was stirred at room temperature. After 1 h DCM (5 mL) was added and the organics washed with saturated aqueous NaHCO₃. The organic extract was passed through a phase separator containing brine (10 mL) and solvent removed under reduced pressure. The resulting residue was purified by column chromatography eluting with 0-10% MeOH/0.7 M NH₃ in DCM to give a white solid, which was taken up in MeOH (3 mL) and filtered through an Amberlite IRA-400 chloride ion exchange resin. The collected MeOH was recycled through the column 3 x. followed by a fresh volume of MeOH. The combined MeOH washings were concentrated under reduced pressure to give the title compound (29 mg) as a white solid.

LC-MS (Method I) 999 [M]⁺; RT 7.78 min

Example 42—5-{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10,13-tetrahydroxy-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}-5-phenyl-5H-benzo[b]phosphindol-5-ium chloride

Prepared following the procedure in Example 41 using 5-{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}-5-phenyl-5H-benzo[b]phosphindol-5-ium chloride (prepared as described in Example 39). Title compound isolated as a white solid.

LC-MS (Method 1) 1018 [M]⁺; RT 8.98 min

Example 43—tricyclohexyl({12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10,13-tetrahydroxy-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl})phosphonium chloride

Prepared following the procedure in Example 41 using tricyclohexyl({12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl})phosphonium chloride (prepared as described in Example 31). Title compound isolated as a white solid.

LC-MS (Method 1) 1038 [M]⁺; RT 10.94 min

Example 44—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10,13-tetrahydroxy-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}tris(3-methylphenyl)phosphonium chloride

Prepared following the procedure in Example 41 using {12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}tris(3-methylphenyl)phosphonium chloride (prepared as described in Example 30). Title compound isolated as a white solid.

LC-MS (Method 1) 1062 [M]⁺; RT 9.71 min

Example 45—{12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10,13-tetrahydroxy-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}tris(3,5-dimethylphenyl)phosphonium chloride

Prepared following the procedure in Example 41 using {12-[(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-{[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy}-2-ethyl-3,4,10-trihydroxy-13-{[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy}-3,5,8,10,12,14-hexamethyl-15-oxo-1-oxa-6-azacyclopentadecan-6-yl]-12-oxododecyl}tris(3,5-dimethylphenyl)phosphonium chloride (prepared as described in Example 29). Title compound isolated as a white solid.

LC-MS (Method 1) 1104 [M]⁺; RT 11.18 min

Inhibition of Proliferation Assay

Cell Confluence

The confluence value is a surrogate for cell proliferation and growth. The value is expressed as a percent confluence, which represents the fraction of culture dish-surface that is occupied by cells. As the number of cells in the dish increases over time due to proliferation, so will their coverage of that surface increase. Expansion of the cell population on the cell culture-dish surface and confluence have mostly a linear relationship until the cells on the plate surface begin to reach saturation or maximum density.

Confluence is determined based on image analysis. Image based software can identify objects in the image field base on changes to pixel density in a grey scale image. The software can then assign a mask to those pixels within the object. Objects can be ‘gated’ out based on size and shape. To determine cell confluence, images of cells are first masked as objects. The surface area of the image that is masked is measured and compared to the total surface area of the culture dish surface to obtain a percent confluence.

MDA-231 cancer cells were obtained from ATCC. Cells were cultured in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM Glutamax, 1 mM Non Essential Amino Acid (NEAA) solution and 1 mM sodium pyruvate. Compounds were dissolved in DMSO at 10 mM and diluted in cellular medium and tested at 10 μM (micromolar). Final DMSO concentrations were 50.1%. Images were acquired with an IncuCyte Live Cell Imaging microscopy (Essen Bioscience) at every 3 h under cell culture conditions with 10× objective over 4-5 d. Cell confluence was calculated from one field of view per well using the IncuCyte in-built algorithm. Relative confluence values were obtained by normalising each value to the time zero value in each sample.

Example Concentration uM % Confluence Azithromycin 100 17 Azithromycin 10 99.1 1 10 4.8 2 10 131.8 3 10 97.7 4 10 87.7 5 10 7.8 6 10 4 7 10 75.3 8 10 83 9 10 70.9 10 10 4 12 10 4.1 13 10 4.8 15 10 16.6 16 10 10 17 10 93.1 18 10 7.7 19 10 10.5 20 10 14.8 21 10 89.9 22 10 137 23 10 7.5 24 10 140 25 10 124 27 10 123 28 10 16 29 10 4.6 30 10 4.4 32 10 129 33 10 5.6 34 10 5.4 35 10 97.2 38 10 135 

The invention claimed is:
 1. A compound comprising an ion of formula (I) or a pharmaceutically acceptable salt thereof:

wherein either Z¹ is

and Z² is R^(4b); or Z² is

and Z¹ is R^(2b); Z³ is independently selected from H, C(O)—C1-C6-alkyl or Z³ has the structure:

Z⁴ is independently selected from H, C(O)—C1-C6-alkyl or Z⁴ has the structure:

-L¹- is independently absent or is selected from —C(O)—, —C(O)O—, —S(O)₂—, —S(O)—, —C(O)NR⁵, and —S(O)₂NR⁵—; -L³- is independently at each occurrence either absent or selected from: —O—, —S—, —NR⁶—, —C(O)—, —OC(O)—, —C(O)O—, —S(O)₂—, —S(O)—, —NR⁵C(O)—, —C(O)NR⁵, —NR⁵S(O)₂—, —S(O)₂NR⁵—, —OC(O)NR⁵—, —NR⁵C(O)O—, NR⁵C(O)NR⁵, —CR⁷═CR⁷— and —C≡C—; -L²- and -L⁴- are each independently at each occurrence —C₁-C₄-alkylene-, each alkylene group being unsubstituted or substituted with from 1 to 6 independently selected R⁸ groups; provided that any -L₂- or -L₄- group that is attached at each end to an atom selected from oxygen, nitrogen, sulphur or phosphorous is —C₂-C₄-alkylene-; -L⁵- is independently absent or is selected from: —C(O)— and —C(O)NR⁵—; n is an integer selected from 0, 1, 2, 3, 4 and 5; wherein L¹, L², L³, L⁴, L⁵ and n are selected such that length of the linker formed by those groups is from 3 to 16 atoms; R^(1a), R^(1b) and R^(1c) are each independently selected from phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl; wherein said phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl is optionally substituted with from 1 to 5 independently selected R^(1d) groups; and wherein said C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl is optionally substituted with from 1 to 5 independently selected R^(1e) groups; provided that R^(1a), R^(1b) and R^(1c) are not each unsubstituted phenyl; wherein R^(1a) and R^(1b) are optionally connected to each other via a bond or a group selected from —O—, NR^(6a), and C₁-C₃-alkylene; R^(1d) is independently at each occurrence selected from: C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, 5- to 8-membered heterocycloalkyl, 5-, 6-, 9- or 10-membered heteroaryl, phenyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R^(1e) is independently at each occurrence selected from: oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, 5- to 8-membered heterocycloalkyl, 5-, 6-, 9- or 10-membered heteroaryl, phenyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R^(2a), R^(2b) and R^(2c) are each independently selected from H and C₁-C₆-alkyl; R^(3a) is independently selected from: H, C₁-C₆-alkyl and C(O)—C₁-C₆-alkyl; R^(3b) and R^(3c) are each independently selected from: H and C(O)—C₁-C₆-alkyl; R^(4a) and R^(4b) are each independently selected from: H, C₁-C₆-alkyl and C(O)—C₁-C₆-alkyl; or R^(4a) and R^(4b) taken together form C(O); R⁵ and R^(6a) are each independently at each occurrence selected from H and C₁-C₆-alkyl; R⁶ and R¹¹ are each independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl; R⁷ is independently at each occurrence selected from H, C₁-C₄-alkyl and halo; R⁸ is independently at each occurrence selected from: C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, OR⁹, SR¹⁰, NR¹⁰R¹¹, C(O)OR¹⁰, C(O)NR¹⁰R¹⁰, halo, cyano, nitro, C(O)R¹⁰, S(O)₂OR¹⁰, S(O)R¹⁰, S(O)₂R¹⁰, S(O)₂NR¹⁰R¹⁰, OC(O)NR¹⁰R¹⁰ and NR¹⁰C(O)OR¹⁰; R⁹ is independently at each occurrence selected from: H, C₁-C₆-alkyl and C₁-C₆-haloalkyl; R¹⁰ is independently at each occurrence selected from: H and C₁-C₆-alkyl; and wherein any of the abovementioned alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, heteroaryl or phenyl groups is optionally substituted where chemically allowable by from 1 to 4 groups independently selected from oxo, C₁-C₆-alkyl, C₂-C₆-alkynyl, C₂-C₆-alkenyl, C₁-C₆-haloalkyl, OR^(a), NR^(a)R^(b), SR^(a), C(O)OR^(a), C(O)NR^(a)R^(a), halo, cyano, nitro, C(O)R^(a), S(O)₂OR^(a), S(O)₂R^(a), S(O)R^(a) and S(O)₂NR^(a)R^(a); wherein R^(a) is independently at each occurrence selected from: H and C₁-C₆-alkyl; and R^(b) is independently at each occurrence selected from: H, C₁-C₆-alkyl, C(O)C₁-C₆-alkyl and S(O)₂—C₁-C₆-alkyl.
 2. The compound of claim 1, wherein Z¹ is

and Z² is R^(4b).
 3. The compound of claim 2, wherein L¹ is selected from —C(O)— and —S(O)₂—.
 4. The compound of claim 2, wherein L¹ is absent.
 5. The compound of claim 2, wherein R^(4a) is H and R^(4b) is H; or wherein R^(4a) and R^(4b) together form C(O).
 6. The compound of claim 1, wherein Z² is

and Z¹ is R^(2b).
 7. The compound of claim 6, wherein L⁵ is —C(O)— or —C(O)NR⁵—.
 8. The compound of claim 6, wherein R^(4a) is H.
 9. The compound of claim 1, wherein L³ is at each occurrence absent.
 10. The compound of claim 1, wherein L¹, L², L³, L⁴, L⁵ and n are selected such that length of the linker formed by those groups is from 8 to 14 atoms.
 11. The compound of claim 1, wherein Z³ is


12. The compound of claim 1, wherein R^(2a) is methyl and R^(2c) is methyl.
 13. The compound of claim 1, wherein R^(3a) is H and R^(3b) is H; or wherein R^(3a) is H and R^(3b) is C(O)CH₃.
 14. The compound of claim 1, wherein R^(1a), R^(1b) and R^(1c) are each substituted phenyl; or wherein R^(1a), R^(1b) and R^(1c) are each C₃ to C₈-cycloalkyl; or wherein R^(1a), R^(1b) and R^(1c) are each benzyl.
 15. The compound of claim 1, wherein R^(1a) and R^(1b) are each unsubstituted phenyl and R^(1c) is independently selected from: substituted phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₃ to C₈-cycloalkyl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl; or wherein R^(1a) and R^(1b) are each C₃ to C₈-cycloalkyl and R^(1c) is independently selected from: phenyl, biphenyl, naphthyl, 5-, 6-, 9- or 10-membered heteroaryl, C₁-C₈-alkyl and 4- to 8-membered heterocycloalkyl.
 16. The compound of claim 1, wherein at least one of R^(1a), R^(1b) and R^(1c) is C₁-C₆-alkyl.
 17. The compound of claim 16, wherein any of R^(1a), R^(1b) and R^(1c) that are not C₁-C₆-alkyl are phenyl.
 18. The compound of claim 1, wherein the cation of formula (I) is selected from:


19. A method for the treatment of cancer, wherein the method comprises the administration of a therapeutically effective amount of a compound of claim
 1. 20. A pharmaceutical composition, wherein the composition comprises a compound of claim 1 and one or more pharmaceutically acceptable excipients. 